638512023 has 4 divisors (see below), whose sum is σ = 851349368. Its totient is φ = 425674680.

The previous prime is 638512013. The next prime is 638512057. The reversal of 638512023 is 320215836.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 638512023 - 2¹⁸ = 638249879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638512013) 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 3 ways as a sum of consecutive naturals, for example, 106418668 + ... + 106418673.

It is an arithmetic number, because the mean of its divisors is an integer number (212837342).

Almost surely, 2^638512023 is an apocalyptic number.

638512023 is a deficient number, since it is larger than the sum of its proper divisors (212837345).

638512023 is a wasteful number, since it uses less digits than its factorization.

638512023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212837344.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 638512023 is about 25268.7954402263. The cubic root of 638512023 is about 861.1054933257.

Adding to 638512023 its reverse (320215836), we get a palindrome (958727859).

The spelling of 638512023 in words is "six hundred thirty-eight million, five hundred twelve thousand, twenty-three".