81580311448877 has 2 divisors, whose sum is σ = 81580311448878. Its totient is φ = 81580311448876.

The previous prime is 81580311448751. The next prime is 81580311448891. The reversal of 81580311448877 is 77884411308518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59651077474921 + 21929233973956 = 7723411^2 + 4682866^2 .

It is a cyclic number.

It is not a de Polignac number, because 81580311448877 - 2¹⁸ = 81580311186733 is a prime.

It is a super-2 number, since 2×81580311448877² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81580311448577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40790155724438 + 40790155724439.

It is an arithmetic number, because the mean of its divisors is an integer number (40790155724439).

Almost surely, 2^{81580311448877} is an apocalyptic number.

It is an amenable number.

81580311448877 is a deficient number, since it is larger than the sum of its proper divisors (1).

81580311448877 is an equidigital number, since it uses as much as digits as its factorization.

81580311448877 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48168960, while the sum is 65.

The spelling of 81580311448877 in words is "eighty-one trillion, five hundred eighty billion, three hundred eleven million, four hundred forty-eight thousand, eight hundred seventy-seven".