81609979674 has 8 divisors (see below), whose sum is σ = 163219959360. Its totient is φ = 27203326556.

The previous prime is 81609979673. The next prime is 81609979679. The reversal of 81609979674 is 47697990618.

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

81609979674 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (81609979673) 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, 6800831634 + ... + 6800831645.

It is an arithmetic number, because the mean of its divisors is an integer number (20402494920).

Almost surely, 2^81609979674 is an apocalyptic number.

81609979674 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81609979674 is a wasteful number, since it uses less digits than its factorization.

81609979674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13601663284.

The product of its (nonzero) digits is 41150592, while the sum is 66.

The spelling of 81609979674 in words is "eighty-one billion, six hundred nine million, nine hundred seventy-nine thousand, six hundred seventy-four".