638424836 has 12 divisors (see below), whose sum is σ = 1276849728. Its totient is φ = 273610632.

The previous prime is 638424799. The next prime is 638424859.

638424836 is nontrivially palindromic in base 10.

638424836 is an admirable number.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

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, 11400416 + ... + 11400471.

It is an arithmetic number, because the mean of its divisors is an integer number (106404144).

Almost surely, 2^638424836 is an apocalyptic number.

It is an amenable number.

638424836 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

638424836 is a wasteful number, since it uses less digits than its factorization.

638424836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22800898 (or 22800896 counting only the distinct ones).

The product of its digits is 663552, while the sum is 44.

The square root of 638424836 is about 25267.0701902694. The cubic root of 638424836 is about 861.0662977066.

The spelling of 638424836 in words is "six hundred thirty-eight million, four hundred twenty-four thousand, eight hundred thirty-six".