638099928 has 48 divisors (see below), whose sum is σ = 1774902480. Its totient is φ = 206950464.

The previous prime is 638099911. The next prime is 638099941. The reversal of 638099928 is 829990836.

It is a super-2 number, since 2×638099928² = 814343036227210368, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117100 + ... + 122427.

It is an arithmetic number, because the mean of its divisors is an integer number (36977135).

Almost surely, 2^638099928 is an apocalyptic number.

It is an amenable number.

638099928 is an abundant number, since it is smaller than the sum of its proper divisors (1136802552).

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

638099928 is a wasteful number, since it uses less digits than its factorization.

638099928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239576 (or 239569 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The square root of 638099928 is about 25260.6398968831. The cubic root of 638099928 is about 860.9202012589.

It can be divided in two parts, 63809 and 9928, that added together give a palindrome (73737).

The spelling of 638099928 in words is "six hundred thirty-eight million, ninety-nine thousand, nine hundred twenty-eight".