638808216 has 32 divisors (see below), whose sum is σ = 1600684800. Its totient is φ = 212447520.

The previous prime is 638808211. The next prime is 638808221. The reversal of 638808216 is 612808836.

It is an interprime number because it is at equal distance from previous prime (638808211) and next prime (638808221).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638808211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19780 + ... + 40851.

It is an arithmetic number, because the mean of its divisors is an integer number (50021400).

Almost surely, 2^638808216 is an apocalyptic number.

It is an amenable number.

638808216 is an abundant number, since it is smaller than the sum of its proper divisors (961876584).

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

638808216 is a wasteful number, since it uses less digits than its factorization.

638808216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61079 (or 61075 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 42.

The square root of 638808216 is about 25274.6556059623. The cubic root of 638808216 is about 861.2386226338.

The spelling of 638808216 in words is "six hundred thirty-eight million, eight hundred eight thousand, two hundred sixteen".