81051058916173 has 2 divisors, whose sum is σ = 81051058916174. Its totient is φ = 81051058916172.

The previous prime is 81051058916083. The next prime is 81051058916203. The reversal of 81051058916173 is 37161985015018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51900108613929 + 29150950302244 = 7204173^2 + 5399162^2 .

It is a cyclic number.

It is not a de Polignac number, because 81051058916173 - 2²⁵ = 81051025361741 is a prime.

It is a super-2 number, since 2×81051058916173² (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 (81051059916173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40525529458086 + 40525529458087.

It is an arithmetic number, because the mean of its divisors is an integer number (40525529458087).

Almost surely, 2^{81051058916173} is an apocalyptic number.

It is an amenable number.

81051058916173 is a deficient number, since it is larger than the sum of its proper divisors (1).

81051058916173 is an equidigital number, since it uses as much as digits as its factorization.

81051058916173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1814400, while the sum is 55.

The spelling of 81051058916173 in words is "eighty-one trillion, fifty-one billion, fifty-eight million, nine hundred sixteen thousand, one hundred seventy-three".