638432253 has 16 divisors (see below), whose sum is σ = 946512000. Its totient is φ = 425312640.

The previous prime is 638432239. The next prime is 638432257. The reversal of 638432253 is 352234836.

It is a happy number.

It is not a de Polignac number, because 638432253 - 2⁹ = 638431741 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638432257) 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, 32973 + ... + 48621.

It is an arithmetic number, because the mean of its divisors is an integer number (59157000).

Almost surely, 2^638432253 is an apocalyptic number.

It is an amenable number.

638432253 is a deficient number, since it is larger than the sum of its proper divisors (308079747).

638432253 is a wasteful number, since it uses less digits than its factorization.

638432253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17169 (or 17163 counting only the distinct ones).

The product of its digits is 103680, while the sum is 36.

The square root of 638432253 is about 25267.2169619054. The cubic root of 638432253 is about 861.0696322176.

The spelling of 638432253 in words is "six hundred thirty-eight million, four hundred thirty-two thousand, two hundred fifty-three".