91573591 has 2 divisors, whose sum is σ = 91573592. Its totient is φ = 91573590.

The previous prime is 91573589. The next prime is 91573607. The reversal of 91573591 is 19537519.

It is a weak prime.

It is an emirp because it is prime and its reverse (19537519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91573591 - 2¹ = 91573589 is a prime.

Together with 91573589, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91573991) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45786795 + 45786796.

It is an arithmetic number, because the mean of its divisors is an integer number (45786796).

Almost surely, 2^91573591 is an apocalyptic number.

91573591 is a deficient number, since it is larger than the sum of its proper divisors (1).

91573591 is an equidigital number, since it uses as much as digits as its factorization.

91573591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42525, while the sum is 40.

The square root of 91573591 is about 9569.4091249147. The cubic root of 91573591 is about 450.7372129996.

The spelling of 91573591 in words is "ninety-one million, five hundred seventy-three thousand, five hundred ninety-one".