91745231 has 2 divisors, whose sum is σ = 91745232. Its totient is φ = 91745230.

The previous prime is 91745221. The next prime is 91745239. The reversal of 91745231 is 13254719.

It is a strong prime.

It is an emirp because it is prime and its reverse (13254719) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91745231 - 2¹⁸ = 91483087 is a prime.

It is a super-2 number, since 2×91745231² = 16834374822486722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91745239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45872615 + 45872616.

It is an arithmetic number, because the mean of its divisors is an integer number (45872616).

Almost surely, 2^91745231 is an apocalyptic number.

91745231 is a deficient number, since it is larger than the sum of its proper divisors (1).

91745231 is an equidigital number, since it uses as much as digits as its factorization.

91745231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 32.

The square root of 91745231 is about 9578.3730873254. The cubic root of 91745231 is about 451.0186487603.

The spelling of 91745231 in words is "ninety-one million, seven hundred forty-five thousand, two hundred thirty-one".