18331272 has 40 divisors (see below), whose sum is σ = 51346350. Its totient is φ = 6110208.

The previous prime is 18331259. The next prime is 18331279. The reversal of 18331272 is 27213381.

It can be written as a sum of positive squares in only one way, i.e., 11329956 + 7001316 = 3366^2 + 2646^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18331279) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 13497 + ... + 14792.

Almost surely, 2^18331272 is an apocalyptic number.

18331272 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18331272 is an abundant number, since it is smaller than the sum of its proper divisors (33015078).

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

18331272 is a wasteful number, since it uses less digits than its factorization.

18331272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28307 (or 28294 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 18331272 is about 4281.5034742483. The cubic root of 18331272 is about 263.6721135968.

The spelling of 18331272 in words is "eighteen million, three hundred thirty-one thousand, two hundred seventy-two".