18400224 has 24 divisors (see below), whose sum is σ = 48300840. Its totient is φ = 6133376.

The previous prime is 18400177. The next prime is 18400237. The reversal of 18400224 is 42200481.

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

It is a self number, because there is not a number n which added to its sum of digits gives 18400224.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95739 + ... + 95930.

It is an arithmetic number, because the mean of its divisors is an integer number (2012535).

Almost surely, 2^18400224 is an apocalyptic number.

It is an amenable number.

18400224 is an abundant number, since it is smaller than the sum of its proper divisors (29900616).

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

18400224 is a wasteful number, since it uses less digits than its factorization.

18400224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191682 (or 191674 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 18400224 is about 4289.5482279606. The cubic root of 18400224 is about 264.0022956642.

The spelling of 18400224 in words is "eighteen million, four hundred thousand, two hundred twenty-four".