18228972 has 24 divisors (see below), whose sum is σ = 44384256. Its totient is φ = 5812048.

The previous prime is 18228971. The next prime is 18228983. The reversal of 18228972 is 27982281.

It is a self number, because there is not a number n which added to its sum of digits gives 18228972.

It is not an unprimeable number, because it can be changed into a prime (18228971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32748 + ... + 33299.

It is an arithmetic number, because the mean of its divisors is an integer number (1849344).

Almost surely, 2^18228972 is an apocalyptic number.

18228972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18228972 is an abundant number, since it is smaller than the sum of its proper divisors (26155284).

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

18228972 is a wasteful number, since it uses less digits than its factorization.

18228972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66077 (or 66075 counting only the distinct ones).

The product of its digits is 32256, while the sum is 39.

The square root of 18228972 is about 4269.5400220633. The cubic root of 18228972 is about 263.1807130726.

The spelling of 18228972 in words is "eighteen million, two hundred twenty-eight thousand, nine hundred seventy-two".