81158126177 has 2 divisors, whose sum is σ = 81158126178. Its totient is φ = 81158126176.

The previous prime is 81158126057. The next prime is 81158126207. The reversal of 81158126177 is 77162185118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79481141776 + 1676984401 = 281924^2 + 40951^2 .

It is a cyclic number.

It is not a de Polignac number, because 81158126177 - 2¹⁸ = 81157864033 is a prime.

It is not a weakly prime, because it can be changed into another prime (81158125177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40579063088 + 40579063089.

It is an arithmetic number, because the mean of its divisors is an integer number (40579063089).

Almost surely, 2^81158126177 is an apocalyptic number.

It is an amenable number.

81158126177 is a deficient number, since it is larger than the sum of its proper divisors (1).

81158126177 is an equidigital number, since it uses as much as digits as its factorization.

81158126177 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 188160, while the sum is 47.

The spelling of 81158126177 in words is "eighty-one billion, one hundred fifty-eight million, one hundred twenty-six thousand, one hundred seventy-seven".