18156228 has 12 divisors (see below), whose sum is σ = 42364560. Its totient is φ = 6052072.

The previous prime is 18156227. The next prime is 18156251. The reversal of 18156228 is 82265181.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (18156227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 756498 + ... + 756521.

It is an arithmetic number, because the mean of its divisors is an integer number (3530380).

Almost surely, 2^18156228 is an apocalyptic number.

It is an amenable number.

18156228 is an abundant number, since it is smaller than the sum of its proper divisors (24208332).

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

18156228 is a wasteful number, since it uses less digits than its factorization.

18156228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1513026 (or 1513024 counting only the distinct ones).

The product of its digits is 7680, while the sum is 33.

The square root of 18156228 is about 4261.0125557196. The cubic root of 18156228 is about 262.8301659573.

The spelling of 18156228 in words is "eighteen million, one hundred fifty-six thousand, two hundred twenty-eight".