18401918 has 16 divisors (see below), whose sum is σ = 29607120. Its totient is φ = 8551296.

The previous prime is 18401857. The next prime is 18401927. The reversal of 18401918 is 81910481.

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 7 ways as a sum of consecutive naturals, for example, 2555 + ... + 6582.

It is an arithmetic number, because the mean of its divisors is an integer number (1850445).

Almost surely, 2^18401918 is an apocalyptic number.

18401918 is a deficient number, since it is larger than the sum of its proper divisors (11205202).

18401918 is a wasteful number, since it uses less digits than its factorization.

18401918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9211.

The product of its (nonzero) digits is 2304, while the sum is 32.

The square root of 18401918 is about 4289.7456801074. The cubic root of 18401918 is about 264.0103971265.

The spelling of 18401918 in words is "eighteen million, four hundred one thousand, nine hundred eighteen".