18820404 has 24 divisors (see below), whose sum is σ = 48793920. Its totient is φ = 6273432.

The previous prime is 18820397. The next prime is 18820421. The reversal of 18820404 is 40402881.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 87024 + ... + 87239.

It is an arithmetic number, because the mean of its divisors is an integer number (2033080).

Almost surely, 2^18820404 is an apocalyptic number.

It is an amenable number.

18820404 is an abundant number, since it is smaller than the sum of its proper divisors (29973516).

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

18820404 is a wasteful number, since it uses less digits than its factorization.

18820404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174276 (or 174268 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 18820404 is about 4338.2489555119. The cubic root of 18820404 is about 265.9967399303.

The spelling of 18820404 in words is "eighteen million, eight hundred twenty thousand, four hundred four".