The least common multiple of two primes is 91, and the sum of the two primes is______ .

The least common multiple of two primes is 91, and the sum of the two primes is______ .

Because 91 = 7 × 13, 91 has only the common factor 1, 7 and 13. The two prime numbers satisfying the condition are 7 and 13, and 7 + 13 = 20, so the answer is: 20