18272720 has 20 divisors (see below), whose sum is σ = 42484260. Its totient is φ = 7309056.

The previous prime is 18272701. The next prime is 18272731. The reversal of 18272720 is 2727281.

It can be written as a sum of positive squares in 2 ways, for example, as 12082576 + 6190144 = 3476^2 + 2488^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 114125 + ... + 114284.

It is an arithmetic number, because the mean of its divisors is an integer number (2124213).

Almost surely, 2^18272720 is an apocalyptic number.

18272720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18272720 is an abundant number, since it is smaller than the sum of its proper divisors (24211540).

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

18272720 is a wasteful number, since it uses less digits than its factorization.

18272720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228422 (or 228416 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 18272720 is about 4274.6602204152. The cubic root of 18272720 is about 263.3910820668.

The spelling of 18272720 in words is "eighteen million, two hundred seventy-two thousand, seven hundred twenty".