91566866519 has 2 divisors, whose sum is σ = 91566866520. Its totient is φ = 91566866518.

The previous prime is 91566866467. The next prime is 91566866537.

91566866519 is nontrivially palindromic in base 10.

It is a strong prime.

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 91566866519 - 2¹² = 91566862423 is a prime.

It is a super-2 number, since 2×91566866519² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91566869519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45783433259 + 45783433260.

It is an arithmetic number, because the mean of its divisors is an integer number (45783433260).

Almost surely, 2^91566866519 is an apocalyptic number.

91566866519 is a deficient number, since it is larger than the sum of its proper divisors (1).

91566866519 is an equidigital number, since it uses as much as digits as its factorization.

91566866519 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20995200, while the sum is 62.

The spelling of 91566866519 in words is "ninety-one billion, five hundred sixty-six million, eight hundred sixty-six thousand, five hundred nineteen".