12931638 has 8 divisors (see below), whose sum is σ = 25863288. Its totient is φ = 4310544.

The previous prime is 12931631. The next prime is 12931643. The reversal of 12931638 is 83613921.

It is a sphenic number, since it is the product of 3 distinct primes.

12931638 is an admirable number.

It is a super-2 number, since 2×12931638² = 334454522726088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12931599 and 12931608.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1077631 + ... + 1077642.

It is an arithmetic number, because the mean of its divisors is an integer number (3232911).

Almost surely, 2^12931638 is an apocalyptic number.

12931638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

12931638 is a wasteful number, since it uses less digits than its factorization.

12931638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2155278.

The product of its digits is 7776, while the sum is 33.

The square root of 12931638 is about 3596.0586758283. The cubic root of 12931638 is about 234.7205853670.

The spelling of 12931638 in words is "twelve million, nine hundred thirty-one thousand, six hundred thirty-eight".