81797132797 has 4 divisors (see below), whose sum is σ = 84435750016. Its totient is φ = 79158515580.

The previous prime is 81797132789. The next prime is 81797132821. The reversal of 81797132797 is 79723179718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81797132797 - 2³ = 81797132789 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 (81797132777) 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, 1319308563 + ... + 1319308624.

It is an arithmetic number, because the mean of its divisors is an integer number (21108937504).

Almost surely, 2^81797132797 is an apocalyptic number.

It is an amenable number.

81797132797 is a deficient number, since it is larger than the sum of its proper divisors (2638617219).

81797132797 is a wasteful number, since it uses less digits than its factorization.

81797132797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2638617218.

The product of its digits is 9335088, while the sum is 61.

The spelling of 81797132797 in words is "eighty-one billion, seven hundred ninety-seven million, one hundred thirty-two thousand, seven hundred ninety-seven".