18311905 has 16 divisors (see below), whose sum is σ = 23224320. Its totient is φ = 13838272.

The previous prime is 18311893. The next prime is 18311947. The reversal of 18311905 is 50911381.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18311905 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5472 + ... + 8158.

It is an arithmetic number, because the mean of its divisors is an integer number (1451520).

Almost surely, 2^18311905 is an apocalyptic number.

It is an amenable number.

18311905 is a deficient number, since it is larger than the sum of its proper divisors (4912415).

18311905 is a wasteful number, since it uses less digits than its factorization.

18311905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2768.

The product of its (nonzero) digits is 1080, while the sum is 28.

The square root of 18311905 is about 4279.2411710489. The cubic root of 18311905 is about 263.5792242939.

The spelling of 18311905 in words is "eighteen million, three hundred eleven thousand, nine hundred five".