638385020100 has 81 divisors (see below), whose sum is σ = 2001057514183. Its totient is φ = 170229613440.

The previous prime is 638385020089. The next prime is 638385020111. The reversal of 638385020100 is 1020583836.

The square root of 638385020100 is 798990.

It is a perfect power (a square), and thus also a powerful number.

638385020100 is a `hidden beast` number, since 63 + 83 + 8 + 502 + 0 + 10 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (638385020089) and next prime (638385020111).

It can be written as a sum of positive squares in 4 ways, for example, as 171808592004 + 466576428096 = 414498^2 + 683064^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 23956384 + ... + 23983016.

Almost surely, 2^638385020100 is an apocalyptic number.

638385020100 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

638385020100 is the 798990-th square number.

It is an amenable number.

638385020100 is an abundant number, since it is smaller than the sum of its proper divisors (1362672494083).

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

638385020100 is an equidigital number, since it uses as much as digits as its factorization.

638385020100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53286 (or 26643 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

Multiplying 638385020100 by its sum of digits (36), we get a square (22981860723600 = 4793940²).

638385020100 divided by its sum of digits (36) gives a square (17732917225 = 133165²).

The spelling of 638385020100 in words is "six hundred thirty-eight billion, three hundred eighty-five million, twenty thousand, one hundred".