638449228956 has 96 divisors (see below), whose sum is σ = 1896824143872. Its totient is φ = 162302639040.

The previous prime is 638449228913. The next prime is 638449228961. The reversal of 638449228956 is 659822944836.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7307236 + ... + 7394091.

It is an arithmetic number, because the mean of its divisors is an integer number (19758584832).

Almost surely, 2^638449228956 is an apocalyptic number.

638449228956 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

638449228956 is an abundant number, since it is smaller than the sum of its proper divisors (1258374914916).

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

638449228956 is a wasteful number, since it uses less digits than its factorization.

638449228956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14701399 (or 14701397 counting only the distinct ones).

The product of its digits is 179159040, while the sum is 66.

The spelling of 638449228956 in words is "six hundred thirty-eight billion, four hundred forty-nine million, two hundred twenty-eight thousand, nine hundred fifty-six".