18821156 has 12 divisors (see below), whose sum is σ = 33174960. Its totient is φ = 9342600.

The previous prime is 18821147. The next prime is 18821161. The reversal of 18821156 is 65112881.

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, 16370 + ... + 17481.

It is an arithmetic number, because the mean of its divisors is an integer number (2764580).

Almost surely, 2^18821156 is an apocalyptic number.

It is an amenable number.

18821156 is a deficient number, since it is larger than the sum of its proper divisors (14353804).

18821156 is a wasteful number, since it uses less digits than its factorization.

18821156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33994 (or 33992 counting only the distinct ones).

The product of its digits is 3840, while the sum is 32.

The square root of 18821156 is about 4338.3356255596. The cubic root of 18821156 is about 266.0002826612. Note that the first 3 decimals are identical.

The spelling of 18821156 in words is "eighteen million, eight hundred twenty-one thousand, one hundred fifty-six".