81199398671 has 16 divisors (see below), whose sum is σ = 84154982400. Its totient is φ = 78265387200.

The previous prime is 81199398667. The next prime is 81199398677. The reversal of 81199398671 is 17689399118.

It is a cyclic number.

It is not a de Polignac number, because 81199398671 - 2² = 81199398667 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 (81199398677) 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, 10134515 + ... + 10142523.

It is an arithmetic number, because the mean of its divisors is an integer number (5259686400).

Almost surely, 2^81199398671 is an apocalyptic number.

81199398671 is a deficient number, since it is larger than the sum of its proper divisors (2955583729).

81199398671 is a wasteful number, since it uses less digits than its factorization.

81199398671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9310.

The product of its digits is 5878656, while the sum is 62.

The spelling of 81199398671 in words is "eighty-one billion, one hundred ninety-nine million, three hundred ninety-eight thousand, six hundred seventy-one".