638951875 has 20 divisors (see below), whose sum is σ = 801812088. Its totient is φ = 509000000.

The previous prime is 638951869. The next prime is 638951879. The reversal of 638951875 is 578159836.

It is not a de Polignac number, because 638951875 - 2⁵ = 638951843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638951879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 154839 + ... + 158911.

Almost surely, 2^638951875 is an apocalyptic number.

638951875 is a deficient number, since it is larger than the sum of its proper divisors (162860213).

638951875 is an equidigital number, since it uses as much as digits as its factorization.

638951875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4344 (or 4329 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 52.

The square root of 638951875 is about 25277.4974038175. The cubic root of 638951875 is about 861.3031779534.

The spelling of 638951875 in words is "six hundred thirty-eight million, nine hundred fifty-one thousand, eight hundred seventy-five".