638384451 has 24 divisors (see below), whose sum is σ = 875190960. Its totient is φ = 413816832.

The previous prime is 638384443. The next prime is 638384479. The reversal of 638384451 is 154483836.

It is not a de Polignac number, because 638384451 - 2³ = 638384443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638384431) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4066065 + ... + 4066221.

It is an arithmetic number, because the mean of its divisors is an integer number (36466290).

Almost surely, 2^638384451 is an apocalyptic number.

638384451 is a deficient number, since it is larger than the sum of its proper divisors (236806509).

638384451 is an equidigital number, since it uses as much as digits as its factorization.

638384451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503 (or 346 counting only the distinct ones).

The product of its digits is 276480, while the sum is 42.

The square root of 638384451 is about 25266.2710149321. The cubic root of 638384451 is about 861.0481410948.

The spelling of 638384451 in words is "six hundred thirty-eight million, three hundred eighty-four thousand, four hundred fifty-one".