81600431177 has 4 divisors (see below), whose sum is σ = 81608952336. Its totient is φ = 81591910020.

The previous prime is 81600431173. The next prime is 81600431191. The reversal of 81600431177 is 77113400618.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 77113400618 = 2 ⋅38556700309.

It is a cyclic number.

It is not a de Polignac number, because 81600431177 - 2² = 81600431173 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81600431177.

It is not an unprimeable number, because it can be changed into a prime (81600431173) 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, 4246199 + ... + 4265372.

It is an arithmetic number, because the mean of its divisors is an integer number (20402238084).

Almost surely, 2^81600431177 is an apocalyptic number.

It is an amenable number.

81600431177 is a deficient number, since it is larger than the sum of its proper divisors (8521159).

81600431177 is an equidigital number, since it uses as much as digits as its factorization.

81600431177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8521158.

The product of its (nonzero) digits is 28224, while the sum is 38.

The spelling of 81600431177 in words is "eighty-one billion, six hundred million, four hundred thirty-one thousand, one hundred seventy-seven".