81172356170743 has 2 divisors, whose sum is σ = 81172356170744. Its totient is φ = 81172356170742.

The previous prime is 81172356170681. The next prime is 81172356170779. The reversal of 81172356170743 is 34707165327118.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81172356170743 - 2⁹ = 81172356170231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81172356173743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40586178085371 + 40586178085372.

It is an arithmetic number, because the mean of its divisors is an integer number (40586178085372).

Almost surely, 2^{81172356170743} is an apocalyptic number.

81172356170743 is a deficient number, since it is larger than the sum of its proper divisors (1).

81172356170743 is an equidigital number, since it uses as much as digits as its factorization.

81172356170743 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5927040, while the sum is 55.

The spelling of 81172356170743 in words is "eighty-one trillion, one hundred seventy-two billion, three hundred fifty-six million, one hundred seventy thousand, seven hundred forty-three".