18297990 has 24 divisors (see below), whose sum is σ = 47575008. Its totient is φ = 4879440.

The previous prime is 18297973. The next prime is 18298009. The reversal of 18297990 is 9979281.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 101566 + ... + 101745.

It is an arithmetic number, because the mean of its divisors is an integer number (1982292).

Almost surely, 2^18297990 is an apocalyptic number.

18297990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18297990 is an abundant number, since it is smaller than the sum of its proper divisors (29277018).

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

18297990 is a wasteful number, since it uses less digits than its factorization.

18297990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203324 (or 203321 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 18297990 is about 4277.6149896876. The cubic root of 18297990 is about 263.5124437976.

The spelling of 18297990 in words is "eighteen million, two hundred ninety-seven thousand, nine hundred ninety".