91566417289 has 2 divisors, whose sum is σ = 91566417290. Its totient is φ = 91566417288.

The previous prime is 91566417119. The next prime is 91566417311. The reversal of 91566417289 is 98271466519.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88304065600 + 3262351689 = 297160^2 + 57117^2 .

It is a cyclic number.

It is not a de Polignac number, because 91566417289 - 2¹³ = 91566409097 is a prime.

It is not a weakly prime, because it can be changed into another prime (91566457289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45783208644 + 45783208645.

It is an arithmetic number, because the mean of its divisors is an integer number (45783208645).

Almost surely, 2^91566417289 is an apocalyptic number.

It is an amenable number.

91566417289 is a deficient number, since it is larger than the sum of its proper divisors (1).

91566417289 is an equidigital number, since it uses as much as digits as its factorization.

91566417289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6531840, while the sum is 58.

The spelling of 91566417289 in words is "ninety-one billion, five hundred sixty-six million, four hundred seventeen thousand, two hundred eighty-nine".