91680205117 has 2 divisors, whose sum is σ = 91680205118. Its totient is φ = 91680205116.

The previous prime is 91680205051. The next prime is 91680205139. The reversal of 91680205117 is 71150208619.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84992073156 + 6688131961 = 291534^2 + 81781^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91680205117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91680205117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91680205187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45840102558 + 45840102559.

It is an arithmetic number, because the mean of its divisors is an integer number (45840102559).

Almost surely, 2^91680205117 is an apocalyptic number.

It is an amenable number.

91680205117 is a deficient number, since it is larger than the sum of its proper divisors (1).

91680205117 is an equidigital number, since it uses as much as digits as its factorization.

91680205117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 40.

The spelling of 91680205117 in words is "ninety-one billion, six hundred eighty million, two hundred five thousand, one hundred seventeen".