18423621 has 12 divisors (see below), whose sum is σ = 27769248. Its totient is φ = 11748264.

The previous prime is 18423611. The next prime is 18423649. The reversal of 18423621 is 12632481.

18423621 is a `hidden beast` number, since 18 + 4 + 23 + 621 = 666.

It is not a de Polignac number, because 18423621 - 2⁶ = 18423557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18423611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44295 + ... + 44708.

It is an arithmetic number, because the mean of its divisors is an integer number (2314104).

Almost surely, 2^18423621 is an apocalyptic number.

It is an amenable number.

18423621 is a deficient number, since it is larger than the sum of its proper divisors (9345627).

18423621 is a wasteful number, since it uses less digits than its factorization.

18423621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89032 (or 89029 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 18423621 is about 4292.2745718325. The cubic root of 18423621 is about 264.1141465756.

It can be divided in two parts, 18423 and 621, that added together give a square (19044 = 138²).

The spelling of 18423621 in words is "eighteen million, four hundred twenty-three thousand, six hundred twenty-one".