81709968339 has 12 divisors (see below), whose sum is σ = 118216807176. Its totient is φ = 54385021152.

The previous prime is 81709968317. The next prime is 81709968343. The reversal of 81709968339 is 93386990718.

It is not a de Polignac number, because 81709968339 - 2⁹ = 81709967827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81709964339) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7351729 + ... + 7362834.

It is an arithmetic number, because the mean of its divisors is an integer number (9851400598).

Almost surely, 2^81709968339 is an apocalyptic number.

81709968339 is a deficient number, since it is larger than the sum of its proper divisors (36506838837).

81709968339 is a wasteful number, since it uses less digits than its factorization.

81709968339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14715186 (or 14715183 counting only the distinct ones).

The product of its (nonzero) digits is 17635968, while the sum is 63.

The spelling of 81709968339 in words is "eighty-one billion, seven hundred nine million, nine hundred sixty-eight thousand, three hundred thirty-nine".