638779748 has 12 divisors (see below), whose sum is σ = 1119487152. Its totient is φ = 318926280.

The previous prime is 638779747. The next prime is 638779751. The reversal of 638779748 is 847977836.

It is not an unprimeable number, because it can be changed into a prime (638779741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112790 + ... + 118317.

It is an arithmetic number, because the mean of its divisors is an integer number (93290596).

Almost surely, 2^638779748 is an apocalyptic number.

It is an amenable number.

638779748 is a deficient number, since it is larger than the sum of its proper divisors (480707404).

638779748 is a wasteful number, since it uses less digits than its factorization.

638779748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231802 (or 231800 counting only the distinct ones).

The product of its digits is 14224896, while the sum is 59.

The square root of 638779748 is about 25274.0924268311. The cubic root of 638779748 is about 861.2258289633.

The spelling of 638779748 in words is "six hundred thirty-eight million, seven hundred seventy-nine thousand, seven hundred forty-eight".