81120279605 has 16 divisors (see below), whose sum is σ = 99828759744. Its totient is φ = 63243438720.

The previous prime is 81120279577. The next prime is 81120279607. The reversal of 81120279605 is 50697202118.

It is not a de Polignac number, because 81120279605 - 2²⁰ = 81119231029 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81120279607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32207 + ... + 404076.

It is an arithmetic number, because the mean of its divisors is an integer number (6239297484).

Almost surely, 2^81120279605 is an apocalyptic number.

It is an amenable number.

81120279605 is a deficient number, since it is larger than the sum of its proper divisors (18708480139).

81120279605 is a wasteful number, since it uses less digits than its factorization.

81120279605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437236.

The product of its (nonzero) digits is 60480, while the sum is 41.

The spelling of 81120279605 in words is "eighty-one billion, one hundred twenty million, two hundred seventy-nine thousand, six hundred five".