91971532241 has 2 divisors, whose sum is σ = 91971532242. Its totient is φ = 91971532240.

The previous prime is 91971532231. The next prime is 91971532243. The reversal of 91971532241 is 14223517919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72781248400 + 19190283841 = 269780^2 + 138529^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91971532241 is a prime.

It is a super-3 number, since 3×91971532241³ (a number of 34 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 91971532243, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 91971532192 and 91971532201.

It is not a weakly prime, because it can be changed into another prime (91971532243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45985766120 + 45985766121.

It is an arithmetic number, because the mean of its divisors is an integer number (45985766121).

Almost surely, 2^91971532241 is an apocalyptic number.

It is an amenable number.

91971532241 is a deficient number, since it is larger than the sum of its proper divisors (1).

91971532241 is an equidigital number, since it uses as much as digits as its factorization.

91971532241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 44.

The spelling of 91971532241 in words is "ninety-one billion, nine hundred seventy-one million, five hundred thirty-two thousand, two hundred forty-one".