18638379 has 6 divisors (see below), whose sum is σ = 26922116. Its totient is φ = 12425580.

The previous prime is 18638363. The next prime is 18638381. The reversal of 18638379 is 97383681.

It is a happy number.

18638379 is a `hidden beast` number, since 1 + 8 + 638 + 3 + 7 + 9 = 666.

It is not a de Polignac number, because 18638379 - 2⁴ = 18638363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18638309) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1035457 + ... + 1035474.

Almost surely, 2^18638379 is an apocalyptic number.

18638379 is a deficient number, since it is larger than the sum of its proper divisors (8283737).

18638379 is a wasteful number, since it uses less digits than its factorization.

18638379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2070937 (or 2070934 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 18638379 is about 4317.2188964656. The cubic root of 18638379 is about 265.1364148726.

The spelling of 18638379 in words is "eighteen million, six hundred thirty-eight thousand, three hundred seventy-nine".