18772428 has 12 divisors (see below), whose sum is σ = 43802360. Its totient is φ = 6257472.

The previous prime is 18772421. The next prime is 18772433. The reversal of 18772428 is 82427781.

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 not an unprimeable number, because it can be changed into a prime (18772421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 782173 + ... + 782196.

Almost surely, 2^18772428 is an apocalyptic number.

It is an amenable number.

18772428 is an abundant number, since it is smaller than the sum of its proper divisors (25029932).

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

18772428 is a wasteful number, since it uses less digits than its factorization.

18772428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1564376 (or 1564374 counting only the distinct ones).

The product of its digits is 50176, while the sum is 39.

The square root of 18772428 is about 4332.7160073100. The cubic root of 18772428 is about 265.7705258951.

The spelling of 18772428 in words is "eighteen million, seven hundred seventy-two thousand, four hundred twenty-eight".