638521383 has 16 divisors (see below), whose sum is σ = 856774656. Its totient is φ = 422983680.

The previous prime is 638521363. The next prime is 638521397. The reversal of 638521383 is 383125836.

It is not a de Polignac number, because 638521383 - 2²⁸ = 370085927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638521313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 433338 + ... + 434808.

It is an arithmetic number, because the mean of its divisors is an integer number (53548416).

Almost surely, 2^638521383 is an apocalyptic number.

638521383 is a deficient number, since it is larger than the sum of its proper divisors (218253273).

638521383 is a wasteful number, since it uses less digits than its factorization.

638521383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2294.

The product of its digits is 103680, while the sum is 39.

The square root of 638521383 is about 25268.9806482177. The cubic root of 638521383 is about 861.1097009771.

The spelling of 638521383 in words is "six hundred thirty-eight million, five hundred twenty-one thousand, three hundred eighty-three".