18366621 has 32 divisors (see below), whose sum is σ = 30777600. Its totient is φ = 9680832.

The previous prime is 18366617. The next prime is 18366629. The reversal of 18366621 is 12666381.

It is not a de Polignac number, because 18366621 - 2² = 18366617 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18366629) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12691 + ... + 14063.

It is an arithmetic number, because the mean of its divisors is an integer number (961800).

Almost surely, 2^18366621 is an apocalyptic number.

It is an amenable number.

18366621 is a deficient number, since it is larger than the sum of its proper divisors (12410979).

18366621 is a wasteful number, since it uses less digits than its factorization.

18366621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1410 (or 1396 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 18366621 is about 4285.6295920203. The cubic root of 18366621 is about 263.8414882931.

The spelling of 18366621 in words is "eighteen million, three hundred sixty-six thousand, six hundred twenty-one".