638635692 has 48 divisors (see below), whose sum is σ = 1518112512. Its totient is φ = 208908480.

The previous prime is 638635691. The next prime is 638635757. The reversal of 638635692 is 296536836.

It is not an unprimeable number, because it can be changed into a prime (638635691) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 234217 + ... + 236927.

It is an arithmetic number, because the mean of its divisors is an integer number (31627344).

Almost surely, 2^638635692 is an apocalyptic number.

It is an amenable number.

638635692 is an abundant number, since it is smaller than the sum of its proper divisors (879476820).

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

638635692 is a wasteful number, since it uses less digits than its factorization.

638635692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3078 (or 3076 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 48.

The square root of 638635692 is about 25271.2423913032. The cubic root of 638635692 is about 861.1610836027.

The spelling of 638635692 in words is "six hundred thirty-eight million, six hundred thirty-five thousand, six hundred ninety-two".