81518116 has 12 divisors (see below), whose sum is σ = 145692288. Its totient is φ = 39891752.

The previous prime is 81518083. The next prime is 81518123. The reversal of 81518116 is 61181518.

It is a happy 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, 216616 + ... + 216991.

It is an arithmetic number, because the mean of its divisors is an integer number (12141024).

Almost surely, 2^81518116 is an apocalyptic number.

It is an amenable number.

81518116 is a deficient number, since it is larger than the sum of its proper divisors (64174172).

81518116 is a wasteful number, since it uses less digits than its factorization.

81518116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433658 (or 433656 counting only the distinct ones).

The product of its digits is 1920, while the sum is 31.

The square root of 81518116 is about 9028.7383393252. The cubic root of 81518116 is about 433.5954451054.

The spelling of 81518116 in words is "eighty-one million, five hundred eighteen thousand, one hundred sixteen".