18131918 has 8 divisors (see below), whose sum is σ = 31083312. Its totient is φ = 7770816.

The previous prime is 18131879. The next prime is 18131921. The reversal of 18131918 is 81913181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 16.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 647555 + ... + 647582.

It is an arithmetic number, because the mean of its divisors is an integer number (3885414).

Almost surely, 2^18131918 is an apocalyptic number.

18131918 is a deficient number, since it is larger than the sum of its proper divisors (12951394).

18131918 is a wasteful number, since it uses less digits than its factorization.

18131918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1295146.

The product of its digits is 1728, while the sum is 32.

The square root of 18131918 is about 4258.1589918649. The cubic root of 18131918 is about 262.7128094388.

The spelling of 18131918 in words is "eighteen million, one hundred thirty-one thousand, nine hundred eighteen".