638684033900 has 72 divisors (see below), whose sum is σ = 1528927611120. Its totient is φ = 229639168000.

The previous prime is 638684033887. The next prime is 638684033921. The reversal of 638684033900 is 9330486836.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3164021 + ... + 3359820.

It is an arithmetic number, because the mean of its divisors is an integer number (21235105710).

Almost surely, 2^638684033900 is an apocalyptic number.

It is an amenable number.

638684033900 is an abundant number, since it is smaller than the sum of its proper divisors (890243577220).

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

638684033900 is a wasteful number, since it uses less digits than its factorization.

638684033900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6523955 (or 6523948 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 50.

The spelling of 638684033900 in words is "six hundred thirty-eight billion, six hundred eighty-four million, thirty-three thousand, nine hundred".