18811020 has 24 divisors (see below), whose sum is σ = 52671024. Its totient is φ = 5016256.

The previous prime is 18810989. The next prime is 18811021. The reversal of 18811020 is 2011881.

It is not an unprimeable number, because it can be changed into a prime (18811021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156699 + ... + 156818.

It is an arithmetic number, because the mean of its divisors is an integer number (2194626).

Almost surely, 2^18811020 is an apocalyptic number.

18811020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18811020 is an abundant number, since it is smaller than the sum of its proper divisors (33860004).

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

18811020 is a wasteful number, since it uses less digits than its factorization.

18811020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313529 (or 313527 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 21.

The square root of 18811020 is about 4337.1672783050. The cubic root of 18811020 is about 265.9525232319.

The spelling of 18811020 in words is "eighteen million, eight hundred eleven thousand, twenty".