638724529 has 9 divisors (see below), whose sum is σ = 647044857. Its totient is φ = 630510804.

The previous prime is 638724517. The next prime is 638724553. The reversal of 638724529 is 925427836.

The square root of 638724529 is 25273.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 638724529 - 2²⁷ = 504506801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638724509) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3209572 + ... + 3209770.

It is an arithmetic number, because the mean of its divisors is an integer number (71893873).

Almost surely, 2^638724529 is an apocalyptic number.

638724529 is the 25273-rd square number.

638724529 is the 12637-th centered octagonal number.

It is an amenable number.

638724529 is a deficient number, since it is larger than the sum of its proper divisors (8320328).

638724529 is an frugal number, since it uses more digits than its factorization.

638724529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652 (or 326 counting only the distinct ones).

The product of its digits is 725760, while the sum is 46.

The cubic root of 638724529 is about 861.2010121677.

The spelling of 638724529 in words is "six hundred thirty-eight million, seven hundred twenty-four thousand, five hundred twenty-nine".