91000831 has 2 divisors, whose sum is σ = 91000832. Its totient is φ = 91000830.

The previous prime is 91000799. The next prime is 91000843. The reversal of 91000831 is 13800019.

It is a strong prime.

It is an emirp because it is prime and its reverse (13800019) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91000831 - 2⁵ = 91000799 is a prime.

It is a super-2 number, since 2×91000831² = 16562302485381122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91000331) 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, 45500415 + 45500416.

It is an arithmetic number, because the mean of its divisors is an integer number (45500416).

Almost surely, 2^91000831 is an apocalyptic number.

91000831 is a deficient number, since it is larger than the sum of its proper divisors (1).

91000831 is an equidigital number, since it uses as much as digits as its factorization.

91000831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 91000831 is about 9539.4355703050. The cubic root of 91000831 is about 449.7955136770.

The spelling of 91000831 in words is "ninety-one million, eight hundred thirty-one", and thus it is an aban number.