639647700 has 72 divisors (see below), whose sum is σ = 1855277088. Its totient is φ = 170152320.

The previous prime is 639647663. The next prime is 639647719. The reversal of 639647700 is 7746936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 130494 + ... + 135306.

Almost surely, 2^639647700 is an apocalyptic number.

639647700 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 639647700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (927638544).

639647700 is an abundant number, since it is smaller than the sum of its proper divisors (1215629388).

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

639647700 is a wasteful number, since it uses less digits than its factorization.

639647700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5273 (or 5266 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 42.

The square root of 639647700 is about 25291.2573827400. The cubic root of 639647700 is about 861.6157204599.

The spelling of 639647700 in words is "six hundred thirty-nine million, six hundred forty-seven thousand, seven hundred".