91665967697 has 2 divisors, whose sum is σ = 91665967698. Its totient is φ = 91665967696.

The previous prime is 91665967693. The next prime is 91665967717. The reversal of 91665967697 is 79676956619.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58730614336 + 32935353361 = 242344^2 + 181481^2 .

It is a cyclic number.

It is not a de Polignac number, because 91665967697 - 2² = 91665967693 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91665967697.

It is not a weakly prime, because it can be changed into another prime (91665967693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45832983848 + 45832983849.

It is an arithmetic number, because the mean of its divisors is an integer number (45832983849).

Almost surely, 2^91665967697 is an apocalyptic number.

It is an amenable number.

91665967697 is a deficient number, since it is larger than the sum of its proper divisors (1).

91665967697 is an equidigital number, since it uses as much as digits as its factorization.

91665967697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 231472080, while the sum is 71.

The spelling of 91665967697 in words is "ninety-one billion, six hundred sixty-five million, nine hundred sixty-seven thousand, six hundred ninety-seven".