18122004 has 18 divisors (see below), whose sum is σ = 45808490. Its totient is φ = 6040656.

The previous prime is 18121997. The next prime is 18122021. The reversal of 18122004 is 40022181.

It can be written as a sum of positive squares in only one way, i.e., 11088900 + 7033104 = 3330^2 + 2652^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 251659 + ... + 251730.

Almost surely, 2^18122004 is an apocalyptic number.

It is an amenable number.

18122004 is an abundant number, since it is smaller than the sum of its proper divisors (27686486).

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

18122004 is a wasteful number, since it uses less digits than its factorization.

18122004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503399 (or 503394 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 18122004 is about 4256.9947145845. The cubic root of 18122004 is about 262.6649194944.

Adding to 18122004 its reverse (40022181), we get a palindrome (58144185).

The spelling of 18122004 in words is "eighteen million, one hundred twenty-two thousand, four".