81170265931493 has 2 divisors, whose sum is σ = 81170265931494. Its totient is φ = 81170265931492.

The previous prime is 81170265931453. The next prime is 81170265931589. The reversal of 81170265931493 is 39413956207118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74932170257569 + 6238095673924 = 8656337^2 + 2497618^2 .

It is a cyclic number.

It is not a de Polignac number, because 81170265931493 - 2¹⁰ = 81170265930469 is a prime.

It is a super-2 number, since 2×81170265931493² (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 (81170265931453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40585132965746 + 40585132965747.

It is an arithmetic number, because the mean of its divisors is an integer number (40585132965747).

It is a 1-persistent number, because it is pandigital, but 2⋅81170265931493 = 162340531862986 is not.

Almost surely, 2^{81170265931493} is an apocalyptic number.

It is an amenable number.

81170265931493 is a deficient number, since it is larger than the sum of its proper divisors (1).

81170265931493 is an equidigital number, since it uses as much as digits as its factorization.

81170265931493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9797760, while the sum is 59.

The spelling of 81170265931493 in words is "eighty-one trillion, one hundred seventy billion, two hundred sixty-five million, nine hundred thirty-one thousand, four hundred ninety-three".