91705751617 has 2 divisors, whose sum is σ = 91705751618. Its totient is φ = 91705751616.

The previous prime is 91705751611. The next prime is 91705751681. The reversal of 91705751617 is 71615750719.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49170401536 + 42535350081 = 221744^2 + 206241^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91705751617 is a prime.

It is a super-2 number, since 2×91705751617² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91705751611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45852875808 + 45852875809.

It is an arithmetic number, because the mean of its divisors is an integer number (45852875809).

Almost surely, 2^91705751617 is an apocalyptic number.

It is an amenable number.

91705751617 is a deficient number, since it is larger than the sum of its proper divisors (1).

91705751617 is an equidigital number, since it uses as much as digits as its factorization.

91705751617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 463050, while the sum is 49.

The spelling of 91705751617 in words is "ninety-one billion, seven hundred five million, seven hundred fifty-one thousand, six hundred seventeen".