638747900 has 36 divisors (see below), whose sum is σ = 1584096528. Its totient is φ = 218999040.

The previous prime is 638747899. The next prime is 638747933. The reversal of 638747900 is 9747836.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 455549 + ... + 456948.

Almost surely, 2^638747900 is an apocalyptic number.

It is an amenable number.

638747900 is an abundant number, since it is smaller than the sum of its proper divisors (945348628).

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

638747900 is a wasteful number, since it uses less digits than its factorization.

638747900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912518 (or 912511 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 44.

The square root of 638747900 is about 25273.4623666802. The cubic root of 638747900 is about 861.2115158525.

The spelling of 638747900 in words is "six hundred thirty-eight million, seven hundred forty-seven thousand, nine hundred".