81324589420117 has 2 divisors, whose sum is σ = 81324589420118. Its totient is φ = 81324589420116.

The previous prime is 81324589420111. The next prime is 81324589420171. The reversal of 81324589420117 is 71102498542318.

Together with next prime (81324589420171) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79610809955121 + 1713779464996 = 8922489^2 + 1309114^2 .

It is a cyclic number.

It is not a de Polignac number, because 81324589420117 - 2¹¹ = 81324589418069 is a prime.

It is a super-3 number, since 3×81324589420117³ (a number of 43 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81324589420111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40662294710058 + 40662294710059.

It is an arithmetic number, because the mean of its divisors is an integer number (40662294710059).

Almost surely, 2^{81324589420117} is an apocalyptic number.

It is an amenable number.

81324589420117 is a deficient number, since it is larger than the sum of its proper divisors (1).

81324589420117 is an equidigital number, since it uses as much as digits as its factorization.

81324589420117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3870720, while the sum is 55.

The spelling of 81324589420117 in words is "eighty-one trillion, three hundred twenty-four billion, five hundred eighty-nine million, four hundred twenty thousand, one hundred seventeen".