638745078 has 16 divisors (see below), whose sum is σ = 1344726720. Its totient is φ = 201708936.

The previous prime is 638745067. The next prime is 638745089. The reversal of 638745078 is 870547836.

It is an interprime number because it is at equal distance from previous prime (638745067) and next prime (638745089).

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2801400 + ... + 2801627.

It is an arithmetic number, because the mean of its divisors is an integer number (84045420).

Almost surely, 2^638745078 is an apocalyptic number.

638745078 is an abundant number, since it is smaller than the sum of its proper divisors (705981642).

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

638745078 is a wasteful number, since it uses less digits than its factorization.

638745078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5603051.

The product of its (nonzero) digits is 1128960, while the sum is 48.

The square root of 638745078 is about 25273.4065373072. The cubic root of 638745078 is about 861.2102475678.

The spelling of 638745078 in words is "six hundred thirty-eight million, seven hundred forty-five thousand, seventy-eight".