18861228 has 48 divisors (see below), whose sum is σ = 51780960. Its totient is φ = 5916672.

The previous prime is 18861209. The next prime is 18861233. The reversal of 18861228 is 82216881.

18861228 is a `hidden beast` number, since 18 + 8 + 612 + 28 = 666.

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 = 18861192 and 18861201.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3301 + ... + 6972.

It is an arithmetic number, because the mean of its divisors is an integer number (1078770).

Almost surely, 2^18861228 is an apocalyptic number.

18861228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18861228 is an abundant number, since it is smaller than the sum of its proper divisors (32919732).

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

18861228 is a wasteful number, since it uses less digits than its factorization.

18861228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10303 (or 10295 counting only the distinct ones).

The product of its digits is 12288, while the sum is 36.

The square root of 18861228 is about 4342.9515309292. The cubic root of 18861228 is about 266.1889286629.

It can be divided in two parts, 188 and 61228, that added together give a palindrome (61416).

The spelling of 18861228 in words is "eighteen million, eight hundred sixty-one thousand, two hundred twenty-eight".