81276047939 has 2 divisors, whose sum is σ = 81276047940. Its totient is φ = 81276047938.

The previous prime is 81276047929. The next prime is 81276048001. The reversal of 81276047939 is 93974067218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81276047939 - 2⁸ = 81276047683 is a prime.

It is a super-2 number, since 2×81276047939² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81276047929) 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, 40638023969 + 40638023970.

It is an arithmetic number, because the mean of its divisors is an integer number (40638023970).

Almost surely, 2^81276047939 is an apocalyptic number.

81276047939 is a deficient number, since it is larger than the sum of its proper divisors (1).

81276047939 is an equidigital number, since it uses as much as digits as its factorization.

81276047939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4572288, while the sum is 56.

The spelling of 81276047939 in words is "eighty-one billion, two hundred seventy-six million, forty-seven thousand, nine hundred thirty-nine".