81118918 has 8 divisors (see below), whose sum is σ = 121723920. Its totient is φ = 40544280.

The previous prime is 81118879. The next prime is 81118949. The reversal of 81118918 is 81981118.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1063 + ... + 12781.

It is an arithmetic number, because the mean of its divisors is an integer number (15215490).

Almost surely, 2^81118918 is an apocalyptic number.

81118918 is a deficient number, since it is larger than the sum of its proper divisors (40605002).

81118918 is a wasteful number, since it uses less digits than its factorization.

81118918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15182.

The product of its digits is 4608, while the sum is 37.

The square root of 81118918 is about 9006.6041325241. The cubic root of 81118918 is about 432.8865075990.

The spelling of 81118918 in words is "eighty-one million, one hundred eighteen thousand, nine hundred eighteen".