18181272 has 16 divisors (see below), whose sum is σ = 45453240. Its totient is φ = 6060416.

The previous prime is 18181259. The next prime is 18181301. The reversal of 18181272 is 27218181.

It is a happy number.

It is an alternating number because its digits alternate between odd and even.

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, 378753 + ... + 378800.

Almost surely, 2^18181272 is an apocalyptic number.

18181272 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18181272 is an abundant number, since it is smaller than the sum of its proper divisors (27271968).

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

18181272 is a wasteful number, since it uses less digits than its factorization.

18181272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 757562 (or 757558 counting only the distinct ones).

The product of its digits is 1792, while the sum is 30.

The square root of 18181272 is about 4263.9502811360. The cubic root of 18181272 is about 262.9509563646.

The spelling of 18181272 in words is "eighteen million, one hundred eighty-one thousand, two hundred seventy-two".