18909418 has 16 divisors (see below), whose sum is σ = 31044384. Its totient is φ = 8566960.

The previous prime is 18909413. The next prime is 18909431. The reversal of 18909418 is 81490981.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (18909413) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6396 + ... + 8872.

It is an arithmetic number, because the mean of its divisors is an integer number (1940274).

Almost surely, 2^18909418 is an apocalyptic number.

18909418 is a deficient number, since it is larger than the sum of its proper divisors (12134966).

18909418 is a wasteful number, since it uses less digits than its factorization.

18909418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2837.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 18909418 is about 4348.4960618586. The cubic root of 18909418 is about 266.4154380428.

The spelling of 18909418 in words is "eighteen million, nine hundred nine thousand, four hundred eighteen".