638164520 has 64 divisors (see below), whose sum is σ = 1671995520. Its totient is φ = 214665984.

The previous prime is 638164489. The next prime is 638164531. The reversal of 638164520 is 25461836.

It is a Harshad number since it is a multiple of its sum of digits (35).

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, 6662 + ... + 36341.

It is an arithmetic number, because the mean of its divisors is an integer number (26124930).

Almost surely, 2^638164520 is an apocalyptic number.

It is an amenable number.

638164520 is an abundant number, since it is smaller than the sum of its proper divisors (1033831000).

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

638164520 is a wasteful number, since it uses less digits than its factorization.

638164520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43074 (or 43070 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 638164520 is about 25261.9183752937. The cubic root of 638164520 is about 860.9492493118.

The spelling of 638164520 in words is "six hundred thirty-eight million, one hundred sixty-four thousand, five hundred twenty".