18518918 has 16 divisors (see below), whose sum is σ = 30590784. Its totient is φ = 8337960.

The previous prime is 18518917. The next prime is 18518953. The reversal of 18518918 is 81981581.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18518917) 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 7 ways as a sum of consecutive naturals, for example, 1580 + ... + 6287.

It is an arithmetic number, because the mean of its divisors is an integer number (1911924).

Almost surely, 2^18518918 is an apocalyptic number.

18518918 is a deficient number, since it is larger than the sum of its proper divisors (12071866).

18518918 is a wasteful number, since it uses less digits than its factorization.

18518918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7987.

The product of its digits is 23040, while the sum is 41.

The square root of 18518918 is about 4303.3612444228. The cubic root of 18518918 is about 264.5687443930.

The spelling of 18518918 in words is "eighteen million, five hundred eighteen thousand, nine hundred eighteen".