91123871 has 2 divisors, whose sum is σ = 91123872. Its totient is φ = 91123870.

The previous prime is 91123847. The next prime is 91123883. The reversal of 91123871 is 17832119.

It is a strong prime.

It is an emirp because it is prime and its reverse (17832119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91123871 - 2²² = 86929567 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91123831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45561935 + 45561936.

It is an arithmetic number, because the mean of its divisors is an integer number (45561936).

Almost surely, 2^91123871 is an apocalyptic number.

91123871 is a deficient number, since it is larger than the sum of its proper divisors (1).

91123871 is an equidigital number, since it uses as much as digits as its factorization.

91123871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 91123871 is about 9545.8824107570. The cubic root of 91123871 is about 449.9981415561.

The spelling of 91123871 in words is "ninety-one million, one hundred twenty-three thousand, eight hundred seventy-one".