If a three digit number is equal to the cubic sum of its digits, for example: 153 = 1 * 1 * 1 + 5 * 5 = 3 * 3 * 3, what is the formula for solving the problem?

You call this number narcissus number mathematically, which sounds good? There are also similar numbers: 371 and 407
371=3*3*3+7*7*7+1*1*1
407=4*4*4+0*0*0+7*7*7
How can you ask this question,

How many are there such numbers that the sum of four digit cubes equals 198
Even number! The number of

198 = 125 + 64 + 8 + 1
The figures are 12 4 5
The composition is even, so the number of digits can only be 2 or 4
When it is 2, there are 6
When it is 4, there are 6, so there are 12 in total

Let the sum of cubes of a certain four digit number be 168. How many such numbers are there?

1³=1
2³=8
3³=27
4³=64
5³=125
168=125+27+8+8
The four numbers are 5, 3, 2, 2
Such numbers are: A4 / 2 = 4 * 3 * 2 * 1 / 2 = 12

In 1994, the number on you is 3. What is the 200th digit (from left to right) of the quotient divided by 13? What is the single digit of the quotient?

In this case, you can calculate several numbers first, and finally find the rule. You will find that the change rule of quotient is: 2, 5, 6, 4, 1, 0, and then continue to cycle, each cycle is 6. So the 200th bit is: 200 △ 6 = 33 2, corresponding to 5. And his quotient is a 1993 digit, that is, 1993 △ 6 = 332 1, corresponding to 2

Divide a three digit by a one digit, the quotient is 36, and the remainder is 8

The remainder is less than the divisor, so the divisor is 9, so 36 × 9 + 8 = 332
The three digit number is 332 and the divisor is 9

Which four digit number divided by which two digit number is more than seven

There are many answers, such as 2239 = 36 * 62 + 7

128 divided by two digits equals one digit

128÷64＝2

What are the numbers of four digits divided by eighty minus the whole number multiplied by eighty and equal to six

6 + 80K (k takes 13 to 124), that is, from 1046 to 9926, 112 numbers are counted every 80,

A number multiplied by the largest one digit, minus the largest one digit, and then divided by the largest one digit, plus the largest one digit, is exactly equal to the largest three digits

[(999-9) × 9 + 9] / 9, = [990 × 9 + 9] / 9, = [8910 + 9] / 9, = 8919 / 9, = 991, answer: this number is 991

Which one is the quotient of the largest three digits minus the smallest three digits?

The largest three digit number is 999, the smallest three digit number is 100, and the subtraction is 999-100 = 899
899 divided by a single digit is a two digit number. Obviously, the minimum number of this single digit can't be 8, it can only be 9

If a three digit number is equal to the cubic sum of its digits, for example: 153 = 1 * 1 * 1 + 5 * 5 = 3 * 3 * 3, what is the formula for solving the problem?