12638840257638 has 72 divisors (see below), whose sum is σ = 31859266041720. Its totient is φ = 3610617716160.

The previous prime is 12638840257597. The next prime is 12638840257663. The reversal of 12638840257638 is 83675204883621.

12638840257638 is a `hidden beast` number, since 1 + 26 + 3 + 8 + 8 + 4 + 0 + 2 + 576 + 38 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5721193 + ... + 7616411.

It is an arithmetic number, because the mean of its divisors is an integer number (442489806135).

Almost surely, 2^{12638840257638} is an apocalyptic number.

12638840257638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12638840257638 is an abundant number, since it is smaller than the sum of its proper divisors (19220425784082).

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

12638840257638 is a wasteful number, since it uses less digits than its factorization.

12638840257638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1902802 (or 1902792 counting only the distinct ones).

The product of its (nonzero) digits is 92897280, while the sum is 63.

The spelling of 12638840257638 in words is "twelve trillion, six hundred thirty-eight billion, eight hundred forty million, two hundred fifty-seven thousand, six hundred thirty-eight".