91055385569 has 2 divisors, whose sum is σ = 91055385570. Its totient is φ = 91055385568.

The previous prime is 91055385523. The next prime is 91055385599. The reversal of 91055385569 is 96558355019.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57546252544 + 33509133025 = 239888^2 + 183055^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91055385569 is a prime.

It is a super-2 number, since 2×91055385569² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91055385599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45527692784 + 45527692785.

It is an arithmetic number, because the mean of its divisors is an integer number (45527692785).

Almost surely, 2^91055385569 is an apocalyptic number.

It is an amenable number.

91055385569 is a deficient number, since it is larger than the sum of its proper divisors (1).

91055385569 is an equidigital number, since it uses as much as digits as its factorization.

91055385569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7290000, while the sum is 56.

The spelling of 91055385569 in words is "ninety-one billion, fifty-five million, three hundred eighty-five thousand, five hundred sixty-nine".