639952208 has 80 divisors (see below), whose sum is σ = 1441514880. Its totient is φ = 269580288.

The previous prime is 639952177. The next prime is 639952217. The reversal of 639952208 is 802259936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2746460 + ... + 2746692.

It is an arithmetic number, because the mean of its divisors is an integer number (18018936).

Almost surely, 2^639952208 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 639952208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (720757440).

639952208 is an abundant number, since it is smaller than the sum of its proper divisors (801562672).

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

639952208 is a wasteful number, since it uses less digits than its factorization.

639952208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 639952208 is about 25297.2766913753. The cubic root of 639952208 is about 861.7524244907.

The spelling of 639952208 in words is "six hundred thirty-nine million, nine hundred fifty-two thousand, two hundred eight".