638477866800 has 600 divisors, whose sum is σ = 2339017431696. Its totient is φ = 166756423680.

The previous prime is 638477866687. The next prime is 638477866801. The reversal of 638477866800 is 8668774836.

638477866800 is a `hidden beast` number, since 6 + 3 + 8 + 477 + 86 + 6 + 80 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (600).

It is not an unprimeable number, because it can be changed into a prime (638477866801) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 427646854 + ... + 427648346.

Almost surely, 2^638477866800 is an apocalyptic number.

638477866800 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 638477866800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1169508715848).

638477866800 is an abundant number, since it is smaller than the sum of its proper divisors (1700539564896).

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

638477866800 is a wasteful number, since it uses less digits than its factorization.

638477866800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1787 (or 1767 counting only the distinct ones).

The product of its (nonzero) digits is 65028096, while the sum is 63.

The spelling of 638477866800 in words is "six hundred thirty-eight billion, four hundred seventy-seven million, eight hundred sixty-six thousand, eight hundred".