18221524 has 24 divisors (see below), whose sum is σ = 32917248. Its totient is φ = 8820960.

The previous prime is 18221519. The next prime is 18221527. The reversal of 18221524 is 42512281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18221527) 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, 18894 + ... + 19834.

It is an arithmetic number, because the mean of its divisors is an integer number (1371552).

Almost surely, 2^18221524 is an apocalyptic number.

It is an amenable number.

18221524 is a deficient number, since it is larger than the sum of its proper divisors (14695724).

18221524 is a wasteful number, since it uses less digits than its factorization.

18221524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1095 (or 1093 counting only the distinct ones).

The product of its digits is 1280, while the sum is 25.

The square root of 18221524 is about 4268.6677078452. The cubic root of 18221524 is about 263.1448646994.

The spelling of 18221524 in words is "eighteen million, two hundred twenty-one thousand, five hundred twenty-four".