81116195999 has 4 divisors (see below), whose sum is σ = 81564351960. Its totient is φ = 80668040040.

The previous prime is 81116195969. The next prime is 81116196019. The reversal of 81116195999 is 99959161118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81116195999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81116195959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 224077709 + ... + 224078070.

It is an arithmetic number, because the mean of its divisors is an integer number (20391087990).

Almost surely, 2^81116195999 is an apocalyptic number.

81116195999 is a deficient number, since it is larger than the sum of its proper divisors (448155961).

81116195999 is a wasteful number, since it uses less digits than its factorization.

81116195999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448155960.

The product of its digits is 1574640, while the sum is 59.

The spelling of 81116195999 in words is "eighty-one billion, one hundred sixteen million, one hundred ninety-five thousand, nine hundred ninety-nine".