18315988 has 12 divisors (see below), whose sum is σ = 32083072. Its totient is φ = 9149400.

The previous prime is 18315977. The next prime is 18315989. The reversal of 18315988 is 88951381.

It is a super-2 number, since 2×18315988² = 670950832832288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18315989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6631 + ... + 8977.

Almost surely, 2^18315988 is an apocalyptic number.

It is an amenable number.

18315988 is a deficient number, since it is larger than the sum of its proper divisors (13767084).

18315988 is a wasteful number, since it uses less digits than its factorization.

18315988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4302 (or 4300 counting only the distinct ones).

The product of its digits is 69120, while the sum is 43.

The square root of 18315988 is about 4279.7182150230. The cubic root of 18315988 is about 263.5988128984.

The spelling of 18315988 in words is "eighteen million, three hundred fifteen thousand, nine hundred eighty-eight".