12931657 has 4 divisors (see below), whose sum is σ = 12939460. Its totient is φ = 12923856.

The previous prime is 12931643. The next prime is 12931661. The reversal of 12931657 is 75613921.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 75613921 = 283 ⋅267187.

It can be written as a sum of positive squares in 2 ways, for example, as 2876416 + 10055241 = 1696^2 + 3171^2 .

It is a cyclic number.

It is not a de Polignac number, because 12931657 - 2¹⁵ = 12898889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12931757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 318 + ... + 5095.

It is an arithmetic number, because the mean of its divisors is an integer number (3234865).

Almost surely, 2^12931657 is an apocalyptic number.

It is an amenable number.

12931657 is a deficient number, since it is larger than the sum of its proper divisors (7803).

12931657 is an equidigital number, since it uses as much as digits as its factorization.

12931657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7802.

The product of its digits is 11340, while the sum is 34.

The square root of 12931657 is about 3596.0613176085. The cubic root of 12931657 is about 234.7207003225.

The spelling of 12931657 in words is "twelve million, nine hundred thirty-one thousand, six hundred fifty-seven".