18815090 has 64 divisors (see below), whose sum is σ = 41658624. Its totient is φ = 5971968.

The previous prime is 18815089. The next prime is 18815143. The reversal of 18815090 is 9051881.

18815090 = 95² + 96² + ... + 385².

It is a happy number.

It is a super-2 number, since 2×18815090² = 708015223416200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115349 + ... + 115511.

It is an arithmetic number, because the mean of its divisors is an integer number (650916).

Almost surely, 2^18815090 is an apocalyptic number.

18815090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18815090 is an abundant number, since it is smaller than the sum of its proper divisors (22843534).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18815090 is a wasteful number, since it uses less digits than its factorization.

18815090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291.

The product of its (nonzero) digits is 2880, while the sum is 32.

The square root of 18815090 is about 4337.6364531851. The cubic root of 18815090 is about 265.9717025695.

The spelling of 18815090 in words is "eighteen million, eight hundred fifteen thousand, ninety".