638563797 has 32 divisors (see below), whose sum is σ = 974088960. Its totient is φ = 413138880.

The previous prime is 638563771. The next prime is 638563817. The reversal of 638563797 is 797365836.

638563797 is a `hidden beast` number, since 6 + 3 + 8 + 563 + 79 + 7 = 666.

It is not a de Polignac number, because 638563797 - 2¹⁵ = 638531029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638563727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 629863 + ... + 630875.

It is an arithmetic number, because the mean of its divisors is an integer number (30440280).

Almost surely, 2^638563797 is an apocalyptic number.

It is an amenable number.

638563797 is a deficient number, since it is larger than the sum of its proper divisors (335525163).

638563797 is a wasteful number, since it uses less digits than its factorization.

638563797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690 (or 1684 counting only the distinct ones).

The product of its digits is 5715360, while the sum is 54.

The square root of 638563797 is about 25269.8198845975. The cubic root of 638563797 is about 861.1287670565.

The spelling of 638563797 in words is "six hundred thirty-eight million, five hundred sixty-three thousand, seven hundred ninety-seven".