638657045236 has 12 divisors (see below), whose sum is σ = 1277314090528. Its totient is φ = 273710162232.

The previous prime is 638657045207. The next prime is 638657045291. The reversal of 638657045236 is 632540756836.

638657045236 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

638657045236 is an admirable number.

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11404590066 + ... + 11404590121.

Almost surely, 2^638657045236 is an apocalyptic number.

It is an amenable number.

638657045236 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.

638657045236 is a wasteful number, since it uses less digits than its factorization.

638657045236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22809180198 (or 22809180196 counting only the distinct ones).

The product of its (nonzero) digits is 21772800, while the sum is 55.

The spelling of 638657045236 in words is "six hundred thirty-eight billion, six hundred fifty-seven million, forty-five thousand, two hundred thirty-six".