12931639 has 6 divisors (see below), whose sum is σ = 15042984. Its totient is φ = 11084220.

The previous prime is 12931631. The next prime is 12931643. The reversal of 12931639 is 93613921.

12931639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12931639 - 2³ = 12931631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12931631) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 131907 + ... + 132004.

It is an arithmetic number, because the mean of its divisors is an integer number (2507164).

Almost surely, 2^12931639 is an apocalyptic number.

12931639 is a deficient number, since it is larger than the sum of its proper divisors (2111345).

12931639 is an equidigital number, since it uses as much as digits as its factorization.

12931639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263925 (or 263918 counting only the distinct ones).

The product of its digits is 8748, while the sum is 34.

The square root of 12931639 is about 3596.0588148694. The cubic root of 12931639 is about 234.7205914173.

The spelling of 12931639 in words is "twelve million, nine hundred thirty-one thousand, six hundred thirty-nine".