12638765840 has 80 divisors (see below), whose sum is σ = 30076075008. Its totient is φ = 4937507328.

The previous prime is 12638765833. The next prime is 12638765869. The reversal of 12638765840 is 4856783621.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 938837 + ... + 952203.

Almost surely, 2^12638765840 is an apocalyptic number.

12638765840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12638765840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15038037504).

12638765840 is an abundant number, since it is smaller than the sum of its proper divisors (17437309168).

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

12638765840 is a wasteful number, since it uses less digits than its factorization.

12638765840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13656 (or 13650 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 50.

The spelling of 12638765840 in words is "twelve billion, six hundred thirty-eight million, seven hundred sixty-five thousand, eight hundred forty".