18204813 has 36 divisors (see below), whose sum is σ = 29427580. Its totient is φ = 10834560.

The previous prime is 18204803. The next prime is 18204817. The reversal of 18204813 is 31840281.

18204813 is a `hidden beast` number, since 182 + 0 + 481 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 14152644 + 4052169 = 3762^2 + 2013^2 .

It is not a de Polignac number, because 18204813 - 2⁶ = 18204749 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18204817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 79383 + ... + 79611.

Almost surely, 2^18204813 is an apocalyptic number.

It is an amenable number.

18204813 is a deficient number, since it is larger than the sum of its proper divisors (11222767).

18204813 is a wasteful number, since it uses less digits than its factorization.

18204813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 18204813 is about 4266.7098565522. The cubic root of 18204813 is about 263.0643965159.

The spelling of 18204813 in words is "eighteen million, two hundred four thousand, eight hundred thirteen".