91159919 has 2 divisors, whose sum is σ = 91159920. Its totient is φ = 91159918.

The previous prime is 91159909. The next prime is 91159949. The reversal of 91159919 is 91995119.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91159919 - 2⁴ = 91159903 is a prime.

It is a super-2 number, since 2×91159919² = 16620261664173122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91159919.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91159909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45579959 + 45579960.

It is an arithmetic number, because the mean of its divisors is an integer number (45579960).

Almost surely, 2^91159919 is an apocalyptic number.

91159919 is a deficient number, since it is larger than the sum of its proper divisors (1).

91159919 is an equidigital number, since it uses as much as digits as its factorization.

91159919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32805, while the sum is 44.

The square root of 91159919 is about 9547.7703679969. The cubic root of 91159919 is about 450.0574724949.

The spelling of 91159919 in words is "ninety-one million, one hundred fifty-nine thousand, nine hundred nineteen".