18919228 has 12 divisors (see below), whose sum is σ = 33575472. Its totient is φ = 9326240.

The previous prime is 18919213. The next prime is 18919237. The reversal of 18919228 is 82291981.

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, 33025 + ... + 33592.

It is an arithmetic number, because the mean of its divisors is an integer number (2797956).

Almost surely, 2^18919228 is an apocalyptic number.

It is an amenable number.

18919228 is a deficient number, since it is larger than the sum of its proper divisors (14656244).

18919228 is a wasteful number, since it uses less digits than its factorization.

18919228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66692 (or 66690 counting only the distinct ones).

The product of its digits is 20736, while the sum is 40.

The square root of 18919228 is about 4349.6238917865. The cubic root of 18919228 is about 266.4615012200.

The spelling of 18919228 in words is "eighteen million, nine hundred nineteen thousand, two hundred twenty-eight".