81369877612739 has 2 divisors, whose sum is σ = 81369877612740. Its totient is φ = 81369877612738.

The previous prime is 81369877612721. The next prime is 81369877612769. The reversal of 81369877612739 is 93721677896318.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81369877612739 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81369877612739.

It is not a weakly prime, because it can be changed into another prime (81369877612769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40684938806369 + 40684938806370.

It is an arithmetic number, because the mean of its divisors is an integer number (40684938806370).

Almost surely, 2^{81369877612739} is an apocalyptic number.

81369877612739 is a deficient number, since it is larger than the sum of its proper divisors (1).

81369877612739 is an equidigital number, since it uses as much as digits as its factorization.

81369877612739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152216576, while the sum is 77.

The spelling of 81369877612739 in words is "eighty-one trillion, three hundred sixty-nine billion, eight hundred seventy-seven million, six hundred twelve thousand, seven hundred thirty-nine".