12731657 has 4 divisors (see below), whose sum is σ = 13480596. Its totient is φ = 11982720.

The previous prime is 12731647. The next prime is 12731659. The reversal of 12731657 is 75613721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4414201 + 8317456 = 2101^2 + 2884^2 .

It is a cyclic number.

It is not a de Polignac number, because 12731657 - 2⁸ = 12731401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12731659) 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, 374444 + ... + 374477.

It is an arithmetic number, because the mean of its divisors is an integer number (3370149).

Almost surely, 2^12731657 is an apocalyptic number.

12731657 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

12731657 is a deficient number, since it is larger than the sum of its proper divisors (748939).

12731657 is an equidigital number, since it uses as much as digits as its factorization.

12731657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748938.

The product of its digits is 8820, while the sum is 32.

The square root of 12731657 is about 3568.1447560322. The cubic root of 12731657 is about 233.5043505892.

The spelling of 12731657 in words is "twelve million, seven hundred thirty-one thousand, six hundred fifty-seven".