91791719 has 2 divisors, whose sum is σ = 91791720. Its totient is φ = 91791718.

The previous prime is 91791701. The next prime is 91791751. The reversal of 91791719 is 91719719.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91791719 - 2¹² = 91787623 is a prime.

It is a super-2 number, since 2×91791719² = 16851439353949922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 91791719.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91721719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45895859 + 45895860.

It is an arithmetic number, because the mean of its divisors is an integer number (45895860).

Almost surely, 2^91791719 is an apocalyptic number.

91791719 is a deficient number, since it is larger than the sum of its proper divisors (1).

91791719 is an equidigital number, since it uses as much as digits as its factorization.

91791719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35721, while the sum is 44.

The square root of 91791719 is about 9580.7994969105. The cubic root of 91791719 is about 451.0948140800.

The spelling of 91791719 in words is "ninety-one million, seven hundred ninety-one thousand, seven hundred nineteen".