91191019 has 2 divisors, whose sum is σ = 91191020. Its totient is φ = 91191018.

The previous prime is 91191007. The next prime is 91191029. The reversal of 91191019 is 91019119.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91191019 - 2⁹ = 91190507 is a prime.

It is a super-2 number, since 2×91191019² = 16631603892516722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91191029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45595509 + 45595510.

It is an arithmetic number, because the mean of its divisors is an integer number (45595510).

Almost surely, 2^91191019 is an apocalyptic number.

91191019 is a deficient number, since it is larger than the sum of its proper divisors (1).

91191019 is an equidigital number, since it uses as much as digits as its factorization.

91191019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729, while the sum is 31.

The square root of 91191019 is about 9549.3988816051. The cubic root of 91191019 is about 450.1086470174.

The spelling of 91191019 in words is "ninety-one million, one hundred ninety-one thousand, nineteen".