91489831 has 2 divisors, whose sum is σ = 91489832. Its totient is φ = 91489830.

The previous prime is 91489829. The next prime is 91489847. The reversal of 91489831 is 13898419.

It is a weak prime.

It is an emirp because it is prime and its reverse (13898419) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91489831 - 2¹ = 91489829 is a prime.

It is a super-2 number, since 2×91489831² = 16740778352817122, which contains 22 as substring.

Together with 91489829, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91489231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45744915 + 45744916.

It is an arithmetic number, because the mean of its divisors is an integer number (45744916).

Almost surely, 2^91489831 is an apocalyptic number.

91489831 is a deficient number, since it is larger than the sum of its proper divisors (1).

91489831 is an equidigital number, since it uses as much as digits as its factorization.

91489831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 43.

The square root of 91489831 is about 9565.0316779402. The cubic root of 91489831 is about 450.5997451802.

The spelling of 91489831 in words is "ninety-one million, four hundred eighty-nine thousand, eight hundred thirty-one".