81707316982177 has 2 divisors, whose sum is σ = 81707316982178. Its totient is φ = 81707316982176.

The previous prime is 81707316982129. The next prime is 81707316982199. The reversal of 81707316982177 is 77128961370718.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61362923235601 + 20344393746576 = 7833449^2 + 4510476^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81707316982177 is a prime.

It is not a weakly prime, because it can be changed into another prime (81707316983177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40853658491088 + 40853658491089.

It is an arithmetic number, because the mean of its divisors is an integer number (40853658491089).

Almost surely, 2^{81707316982177} is an apocalyptic number.

It is an amenable number.

81707316982177 is a deficient number, since it is larger than the sum of its proper divisors (1).

81707316982177 is an equidigital number, since it uses as much as digits as its factorization.

81707316982177 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 49787136, while the sum is 67.

The spelling of 81707316982177 in words is "eighty-one trillion, seven hundred seven billion, three hundred sixteen million, nine hundred eighty-two thousand, one hundred seventy-seven".