81976320539 has 2 divisors, whose sum is σ = 81976320540. Its totient is φ = 81976320538.

The previous prime is 81976320463. The next prime is 81976320541. The reversal of 81976320539 is 93502367918.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81976320539 is a prime.

It is a super-2 number, since 2×81976320539² (a number of 23 digits) contains 22 as substring.

Together with 81976320541, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81976322539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40988160269 + 40988160270.

It is an arithmetic number, because the mean of its divisors is an integer number (40988160270).

Almost surely, 2^81976320539 is an apocalyptic number.

81976320539 is a deficient number, since it is larger than the sum of its proper divisors (1).

81976320539 is an equidigital number, since it uses as much as digits as its factorization.

81976320539 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2449440, while the sum is 53.

The spelling of 81976320539 in words is "eighty-one billion, nine hundred seventy-six million, three hundred twenty thousand, five hundred thirty-nine".