18091224 has 48 divisors (see below), whose sum is σ = 50328720. Its totient is φ = 5866560.

The previous prime is 18091217. The next prime is 18091243. The reversal of 18091224 is 42219081.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 732 + ... + 6059.

It is an arithmetic number, because the mean of its divisors is an integer number (1048515).

Almost surely, 2^18091224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18091224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25164360).

18091224 is an abundant number, since it is smaller than the sum of its proper divisors (32237496).

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

18091224 is a wasteful number, since it uses less digits than its factorization.

18091224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6840 (or 6833 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 18091224 is about 4253.3779516991. The cubic root of 18091224 is about 262.5161241796.

The spelling of 18091224 in words is "eighteen million, ninety-one thousand, two hundred twenty-four".