18685224 has 24 divisors (see below), whose sum is σ = 50606010. Its totient is φ = 6228384.

The previous prime is 18685213. The next prime is 18685231. The reversal of 18685224 is 42258681.

It can be written as a sum of positive squares in only one way, i.e., 11492100 + 7193124 = 3390^2 + 2682^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 5 ways as a sum of consecutive naturals, for example, 129687 + ... + 129830.

Almost surely, 2^18685224 is an apocalyptic number.

It is an amenable number.

18685224 is an abundant number, since it is smaller than the sum of its proper divisors (31920786).

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

18685224 is a wasteful number, since it uses less digits than its factorization.

18685224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259529 (or 259522 counting only the distinct ones).

The product of its digits is 30720, while the sum is 36.

The square root of 18685224 is about 4322.6408594747. The cubic root of 18685224 is about 265.3583569967.

The spelling of 18685224 in words is "eighteen million, six hundred eighty-five thousand, two hundred twenty-four".