12931640 has 32 divisors (see below), whose sum is σ = 29302560. Its totient is φ = 5136000.

The previous prime is 12931631. The next prime is 12931643. The reversal of 12931640 is 4613921.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12931643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4970 + ... + 7110.

It is an arithmetic number, because the mean of its divisors is an integer number (915705).

Almost surely, 2^12931640 is an apocalyptic number.

12931640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12931640 is an abundant number, since it is smaller than the sum of its proper divisors (16370920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12931640 is a wasteful number, since it uses less digits than its factorization.

12931640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2303 (or 2299 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 12931640 is about 3596.0589539105. The cubic root of 12931640 is about 234.7205974676.

The spelling of 12931640 in words is "twelve million, nine hundred thirty-one thousand, six hundred forty".