638688120 has 64 divisors (see below), whose sum is σ = 2189790720. Its totient is φ = 145985664.

The previous prime is 638688103. The next prime is 638688137. The reversal of 638688120 is 21886836.

It is an interprime number because it is at equal distance from previous prime (638688103) and next prime (638688137).

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 379332 + ... + 381011.

It is an arithmetic number, because the mean of its divisors is an integer number (34215480).

Almost surely, 2^638688120 is an apocalyptic number.

638688120 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638688120 is an abundant number, since it is smaller than the sum of its proper divisors (1551102600).

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

638688120 is a wasteful number, since it uses less digits than its factorization.

638688120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760364 (or 760360 counting only the distinct ones).

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

The square root of 638688120 is about 25272.2796755655. The cubic root of 638688120 is about 861.1846482726.

The spelling of 638688120 in words is "six hundred thirty-eight million, six hundred eighty-eight thousand, one hundred twenty".