638779464 has 48 divisors (see below), whose sum is σ = 1751942400. Its totient is φ = 210229344.

The previous prime is 638779457. The next prime is 638779481. The reversal of 638779464 is 464977836.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 638779464.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50464 + ... + 61839.

It is an arithmetic number, because the mean of its divisors is an integer number (36498800).

Almost surely, 2^638779464 is an apocalyptic number.

It is an amenable number.

638779464 is an abundant number, since it is smaller than the sum of its proper divisors (1113162936).

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

638779464 is a wasteful number, since it uses less digits than its factorization.

638779464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112394 (or 112387 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 54.

The square root of 638779464 is about 25274.0868084289. The cubic root of 638779464 is about 861.2257013303.

The spelling of 638779464 in words is "six hundred thirty-eight million, seven hundred seventy-nine thousand, four hundred sixty-four".