639907952 has 40 divisors (see below), whose sum is σ = 1282239360. Its totient is φ = 309047040.

The previous prime is 639907927. The next prime is 639907981. The reversal of 639907952 is 259709936.

It is a self number, because there is not a number n which added to its sum of digits gives 639907952.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 382574 + ... + 384242.

It is an arithmetic number, because the mean of its divisors is an integer number (32055984).

Almost surely, 2^639907952 is an apocalyptic number.

639907952 is a gapful number since it is divisible by the number (62) 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 639907952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (641119680).

639907952 is an abundant number, since it is smaller than the sum of its proper divisors (642331408).

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

639907952 is a wasteful number, since it uses less digits than its factorization.

639907952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2481 (or 2475 counting only the distinct ones).

The product of its (nonzero) digits is 918540, while the sum is 50.

The square root of 639907952 is about 25296.4019575907. The cubic root of 639907952 is about 861.7325591560.

The spelling of 639907952 in words is "six hundred thirty-nine million, nine hundred seven thousand, nine hundred fifty-two".