81697597417 has 2 divisors, whose sum is σ = 81697597418. Its totient is φ = 81697597416.

The previous prime is 81697597411. The next prime is 81697597447. The reversal of 81697597417 is 71479579618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52763927616 + 28933669801 = 229704^2 + 170099^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81697597417 is a prime.

It is not a weakly prime, because it can be changed into another prime (81697597411) 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, 40848798708 + 40848798709.

It is an arithmetic number, because the mean of its divisors is an integer number (40848798709).

Almost surely, 2^81697597417 is an apocalyptic number.

It is an amenable number.

81697597417 is a deficient number, since it is larger than the sum of its proper divisors (1).

81697597417 is an equidigital number, since it uses as much as digits as its factorization.

81697597417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26671680, while the sum is 64.

The spelling of 81697597417 in words is "eighty-one billion, six hundred ninety-seven million, five hundred ninety-seven thousand, four hundred seventeen".