81654695999 has 4 divisors (see below), whose sum is σ = 81915573936. Its totient is φ = 81393818064.

The previous prime is 81654695929. The next prime is 81654696047. The reversal of 81654695999 is 99959645618.

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

It is a cyclic number.

It is not a de Polignac number, because 81654695999 - 2³⁶ = 12935219263 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 (81654695929) 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, 130438499 + ... + 130439124.

It is an arithmetic number, because the mean of its divisors is an integer number (20478893484).

Almost surely, 2^81654695999 is an apocalyptic number.

81654695999 is a deficient number, since it is larger than the sum of its proper divisors (260877937).

81654695999 is a wasteful number, since it uses less digits than its factorization.

81654695999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260877936.

The product of its digits is 188956800, while the sum is 71.

The spelling of 81654695999 in words is "eighty-one billion, six hundred fifty-four million, six hundred ninety-five thousand, nine hundred ninety-nine".