81097374118777 has 2 divisors, whose sum is σ = 81097374118778. Its totient is φ = 81097374118776.

The previous prime is 81097374118759. The next prime is 81097374118799. The reversal of 81097374118777 is 77781147379018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42563933002816 + 38533441115961 = 6524104^2 + 6207531^2 .

It is a cyclic number.

It is not a de Polignac number, because 81097374118777 - 2²⁷ = 81097239901049 is a prime.

It is not a weakly prime, because it can be changed into another prime (81097374118727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40548687059388 + 40548687059389.

It is an arithmetic number, because the mean of its divisors is an integer number (40548687059389).

Almost surely, 2^{81097374118777} is an apocalyptic number.

It is an amenable number.

81097374118777 is a deficient number, since it is larger than the sum of its proper divisors (1).

81097374118777 is an equidigital number, since it uses as much as digits as its factorization.

81097374118777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116169984, while the sum is 70.

The spelling of 81097374118777 in words is "eighty-one trillion, ninety-seven billion, three hundred seventy-four million, one hundred eighteen thousand, seven hundred seventy-seven".