638654006400 has 96 divisors (see below), whose sum is σ = 2103566665200. Its totient is φ = 170307732480.

The previous prime is 638654006399. The next prime is 638654006489. The reversal of 638654006400 is 4600456836.

It is a tau number, because it is divible by the number of its divisors (96).

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 11 ways as a sum of consecutive naturals, for example, 33253630 + ... + 33272829.

Almost surely, 2^638654006400 is an apocalyptic number.

638654006400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638654006400 is an abundant number, since it is smaller than the sum of its proper divisors (1464912658800).

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

638654006400 is a wasteful number, since it uses less digits than its factorization.

638654006400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66526486 (or 66526469 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 42.

The spelling of 638654006400 in words is "six hundred thirty-eight billion, six hundred fifty-four million, six thousand, four hundred".