81636367259539 has 2 divisors, whose sum is σ = 81636367259540. Its totient is φ = 81636367259538.

The previous prime is 81636367259479. The next prime is 81636367259617. The reversal of 81636367259539 is 93595276363618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81636367259539 - 2¹³ = 81636367251347 is a prime.

It is not a weakly prime, because it can be changed into another prime (81636367259039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40818183629769 + 40818183629770.

It is an arithmetic number, because the mean of its divisors is an integer number (40818183629770).

Almost surely, 2^{81636367259539} is an apocalyptic number.

81636367259539 is a deficient number, since it is larger than the sum of its proper divisors (1).

81636367259539 is an equidigital number, since it uses as much as digits as its factorization.

81636367259539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1322697600, while the sum is 73.

The spelling of 81636367259539 in words is "eighty-one trillion, six hundred thirty-six billion, three hundred sixty-seven million, two hundred fifty-nine thousand, five hundred thirty-nine".