91135823 has 2 divisors, whose sum is σ = 91135824. Its totient is φ = 91135822.

The previous prime is 91135819. The next prime is 91135871. The reversal of 91135823 is 32853119.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91135823 - 2² = 91135819 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91135823.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91135873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45567911 + 45567912.

It is an arithmetic number, because the mean of its divisors is an integer number (45567912).

Almost surely, 2^91135823 is an apocalyptic number.

91135823 is a deficient number, since it is larger than the sum of its proper divisors (1).

91135823 is an equidigital number, since it uses as much as digits as its factorization.

91135823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 32.

The square root of 91135823 is about 9546.5084193123. The cubic root of 91135823 is about 450.0178149326.

The spelling of 91135823 in words is "ninety-one million, one hundred thirty-five thousand, eight hundred twenty-three".