639055872 has 384 divisors, whose sum is σ = 2348236800. Its totient is φ = 167215104.

The previous prime is 639055871. The next prime is 639055883. The reversal of 639055872 is 278550936.

It is a happy number.

639055872 is a `hidden beast` number, since 6 + 3 + 90 + 558 + 7 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639055871) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5031873 + ... + 5031999.

It is an arithmetic number, because the mean of its divisors is an integer number (6115200).

Almost surely, 2^639055872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639055872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1174118400).

639055872 is an abundant number, since it is smaller than the sum of its proper divisors (1709180928).

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

639055872 is a wasteful number, since it uses less digits than its factorization.

639055872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The square root of 639055872 is about 25279.5544264530. The cubic root of 639055872 is about 861.3499045228.

The spelling of 639055872 in words is "six hundred thirty-nine million, fifty-five thousand, eight hundred seventy-two".