91159961 has 2 divisors, whose sum is σ = 91159962. Its totient is φ = 91159960.

The previous prime is 91159951. The next prime is 91159969. The reversal of 91159961 is 16995119.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87235600 + 3924361 = 9340^2 + 1981^2 .

It is an emirp because it is prime and its reverse (16995119) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91159961 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (91159969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45579980 + 45579981.

It is an arithmetic number, because the mean of its divisors is an integer number (45579981).

Almost surely, 2^91159961 is an apocalyptic number.

It is an amenable number.

91159961 is a deficient number, since it is larger than the sum of its proper divisors (1).

91159961 is an equidigital number, since it uses as much as digits as its factorization.

91159961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21870, while the sum is 41.

The square root of 91159961 is about 9547.7725674631. The cubic root of 91159961 is about 450.0575416130.

The spelling of 91159961 in words is "ninety-one million, one hundred fifty-nine thousand, nine hundred sixty-one".