18915228 has 24 divisors (see below), whose sum is σ = 49039760. Its totient is φ = 6305040.

The previous prime is 18915209. The next prime is 18915283. The reversal of 18915228 is 82251981.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18915192 and 18915201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87463 + ... + 87678.

Almost surely, 2^18915228 is an apocalyptic number.

18915228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18915228 is an abundant number, since it is smaller than the sum of its proper divisors (30124532).

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

18915228 is a wasteful number, since it uses less digits than its factorization.

18915228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175154 (or 175146 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 18915228 is about 4349.1640576092. The cubic root of 18915228 is about 266.4427210117.

The spelling of 18915228 in words is "eighteen million, nine hundred fifteen thousand, two hundred twenty-eight".