91509942697 has 2 divisors, whose sum is σ = 91509942698. Its totient is φ = 91509942696.

The previous prime is 91509942659. The next prime is 91509942739. The reversal of 91509942697 is 79624990519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89555949081 + 1953993616 = 299259^2 + 44204^2 .

It is a cyclic number.

It is not a de Polignac number, because 91509942697 - 2¹¹ = 91509940649 is a prime.

It is a super-2 number, since 2×91509942697² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91509942647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45754971348 + 45754971349.

It is an arithmetic number, because the mean of its divisors is an integer number (45754971349).

Almost surely, 2^91509942697 is an apocalyptic number.

It is an amenable number.

91509942697 is a deficient number, since it is larger than the sum of its proper divisors (1).

91509942697 is an equidigital number, since it uses as much as digits as its factorization.

91509942697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11022480, while the sum is 61.

The spelling of 91509942697 in words is "ninety-one billion, five hundred nine million, nine hundred forty-two thousand, six hundred ninety-seven".