91561593601 has 2 divisors, whose sum is σ = 91561593602. Its totient is φ = 91561593600.

The previous prime is 91561593553. The next prime is 91561593631. The reversal of 91561593601 is 10639516519.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78063801201 + 13497792400 = 279399^2 + 116180^2 .

It is an emirp because it is prime and its reverse (10639516519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91561593601 - 2²⁷ = 91427375873 is a prime.

It is not a weakly prime, because it can be changed into another prime (91561593631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45780796800 + 45780796801.

It is an arithmetic number, because the mean of its divisors is an integer number (45780796801).

Almost surely, 2^91561593601 is an apocalyptic number.

It is an amenable number.

91561593601 is a deficient number, since it is larger than the sum of its proper divisors (1).

91561593601 is an equidigital number, since it uses as much as digits as its factorization.

91561593601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 218700, while the sum is 46.

The spelling of 91561593601 in words is "ninety-one billion, five hundred sixty-one million, five hundred ninety-three thousand, six hundred one".