638818874 has 8 divisors (see below), whose sum is σ = 1008661440. Its totient is φ = 302598396.

The previous prime is 638818867. The next prime is 638818883. The reversal of 638818874 is 478818836.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8405474 + ... + 8405549.

It is an arithmetic number, because the mean of its divisors is an integer number (126082680).

Almost surely, 2^638818874 is an apocalyptic number.

638818874 is a deficient number, since it is larger than the sum of its proper divisors (369842566).

638818874 is a wasteful number, since it uses less digits than its factorization.

638818874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16811044.

The product of its digits is 2064384, while the sum is 53.

The square root of 638818874 is about 25274.8664487075. The cubic root of 638818874 is about 861.2434122978.

The spelling of 638818874 in words is "six hundred thirty-eight million, eight hundred eighteen thousand, eight hundred seventy-four".