18891228 has 12 divisors (see below), whose sum is σ = 44079560. Its totient is φ = 6297072.

The previous prime is 18891193. The next prime is 18891251. The reversal of 18891228 is 82219881.

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

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 787123 + ... + 787146.

Almost surely, 2^18891228 is an apocalyptic number.

It is an amenable number.

18891228 is an abundant number, since it is smaller than the sum of its proper divisors (25188332).

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

18891228 is a wasteful number, since it uses less digits than its factorization.

18891228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1574276 (or 1574274 counting only the distinct ones).

The product of its digits is 18432, while the sum is 39.

The square root of 18891228 is about 4346.4040309203. The cubic root of 18891228 is about 266.3299841249.

The spelling of 18891228 in words is "eighteen million, eight hundred ninety-one thousand, two hundred twenty-eight".