18516404 has 6 divisors (see below), whose sum is σ = 32403714. Its totient is φ = 9258200.

The previous prime is 18516401. The next prime is 18516409. The reversal of 18516404 is 40461581.

It can be written as a sum of positive squares in only one way, i.e., 16826404 + 1690000 = 4102^2 + 1300^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18516401) 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 as a sum of consecutive naturals, namely, 2314547 + ... + 2314554.

It is an arithmetic number, because the mean of its divisors is an integer number (5400619).

Almost surely, 2^18516404 is an apocalyptic number.

It is an amenable number.

18516404 is a deficient number, since it is larger than the sum of its proper divisors (13887310).

18516404 is a wasteful number, since it uses less digits than its factorization.

18516404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4629105 (or 4629103 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 18516404 is about 4303.0691372554. The cubic root of 18516404 is about 264.5567718446.

Adding to 18516404 its reverse (40461581), we get a palindrome (58977985).

The spelling of 18516404 in words is "eighteen million, five hundred sixteen thousand, four hundred four".