18408990 has 16 divisors (see below), whose sum is σ = 44181648. Its totient is φ = 4909056.

The previous prime is 18408989. The next prime is 18408991. The reversal of 18408990 is 9980481.

It is an interprime number because it is at equal distance from previous prime (18408989) and next prime (18408991).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18408991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 306787 + ... + 306846.

It is an arithmetic number, because the mean of its divisors is an integer number (2761353).

Almost surely, 2^18408990 is an apocalyptic number.

18408990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18408990 is an abundant number, since it is smaller than the sum of its proper divisors (25772658).

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

18408990 is a wasteful number, since it uses less digits than its factorization.

18408990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613643.

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 18408990 is about 4290.5698922171. The cubic root of 18408990 is about 264.0442132103.

The spelling of 18408990 in words is "eighteen million, four hundred eight thousand, nine hundred ninety".