638836128850 has 48 divisors (see below), whose sum is σ = 1250945246880. Its totient is φ = 242052105600.

The previous prime is 638836128817. The next prime is 638836128851. The reversal of 638836128850 is 58821638836.

It is a happy number.

It is a super-2 number, since 2×638836128850² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638836128851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7551285 + ... + 7635415.

It is an arithmetic number, because the mean of its divisors is an integer number (26061359310).

Almost surely, 2^638836128850 is an apocalyptic number.

638836128850 is a deficient number, since it is larger than the sum of its proper divisors (612109118030).

638836128850 is a wasteful number, since it uses less digits than its factorization.

638836128850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92155 (or 92150 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 58.

The spelling of 638836128850 in words is "six hundred thirty-eight billion, eight hundred thirty-six million, one hundred twenty-eight thousand, eight hundred fifty".