639641600 has 216 divisors, whose sum is σ = 1764789390. Its totient is φ = 228556800.

The previous prime is 639641581. The next prime is 639641617. The reversal of 639641600 is 6146936.

It can be written as a sum of positive squares in 3 ways, for example, as 355247104 + 284394496 = 18848^2 + 16864^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 20633585 + ... + 20633615.

Almost surely, 2^639641600 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 639641600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (882394695).

639641600 is an abundant number, since it is smaller than the sum of its proper divisors (1125147790).

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

639641600 is a wasteful number, since it uses less digits than its factorization.

639641600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 639641600 is about 25291.1367874202. The cubic root of 639641600 is about 861.6129815185.

The spelling of 639641600 in words is "six hundred thirty-nine million, six hundred forty-one thousand, six hundred".