638262935520 has 768 divisors, whose sum is σ = 2579989708800. Its totient is φ = 129113948160.

The previous prime is 638262935509. The next prime is 638262935549. The reversal of 638262935520 is 25539262836.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 150851805 + ... + 150856035.

It is an arithmetic number, because the mean of its divisors is an integer number (3359361600).

Almost surely, 2^638262935520 is an apocalyptic number.

638262935520 is a gapful number since it is divisible by the number (60) 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 638262935520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1289994854400).

638262935520 is an abundant number, since it is smaller than the sum of its proper divisors (1941726773280).

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

638262935520 is a wasteful number, since it uses less digits than its factorization.

638262935520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4431 (or 4423 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 51.

The spelling of 638262935520 in words is "six hundred thirty-eight billion, two hundred sixty-two million, nine hundred thirty-five thousand, five hundred twenty".