638877275 has 6 divisors (see below), whose sum is σ = 792207852. Its totient is φ = 511101800.

The previous prime is 638877271. The next prime is 638877277. The reversal of 638877275 is 572778836.

It is not a de Polignac number, because 638877275 - 2² = 638877271 is a prime.

It is a super-2 number, since 2×638877275² = 816328345022851250, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638877271) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12777521 + ... + 12777570.

It is an arithmetic number, because the mean of its divisors is an integer number (132034642).

Almost surely, 2^638877275 is an apocalyptic number.

638877275 is a deficient number, since it is larger than the sum of its proper divisors (153330577).

638877275 is a wasteful number, since it uses less digits than its factorization.

638877275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25555101 (or 25555096 counting only the distinct ones).

The product of its digits is 3951360, while the sum is 53.

The square root of 638877275 is about 25276.0217399812. The cubic root of 638877275 is about 861.2696565359.

The spelling of 638877275 in words is "six hundred thirty-eight million, eight hundred seventy-seven thousand, two hundred seventy-five".