18390645 has 80 divisors (see below), whose sum is σ = 40656000. Its totient is φ = 7744896.

The previous prime is 18390643. The next prime is 18390661. The reversal of 18390645 is 54609381.

18390645 is a `hidden beast` number, since 1 + 8 + 3 + 9 + 0 + 645 = 666.

It is not a de Polignac number, because 18390645 - 2¹ = 18390643 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18390641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 36606 + ... + 37104.

It is an arithmetic number, because the mean of its divisors is an integer number (508200).

Almost surely, 2^18390645 is an apocalyptic number.

18390645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18390645 is an abundant number, since it is smaller than the sum of its proper divisors (22265355).

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

18390645 is a wasteful number, since it uses less digits than its factorization.

18390645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536 (or 527 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 18390645 is about 4288.4315314576. The cubic root of 18390645 is about 263.9564752626.

The spelling of 18390645 in words is "eighteen million, three hundred ninety thousand, six hundred forty-five".