91893391 has 2 divisors, whose sum is σ = 91893392. Its totient is φ = 91893390.

The previous prime is 91893377. The next prime is 91893421. The reversal of 91893391 is 19339819.

It is a weak prime.

It is an emirp because it is prime and its reverse (19339819) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91893391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91893371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45946695 + 45946696.

It is an arithmetic number, because the mean of its divisors is an integer number (45946696).

Almost surely, 2^91893391 is an apocalyptic number.

91893391 is a deficient number, since it is larger than the sum of its proper divisors (1).

91893391 is an equidigital number, since it uses as much as digits as its factorization.

91893391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488, while the sum is 43.

The square root of 91893391 is about 9586.1040574365. The cubic root of 91893391 is about 451.2613025512.

The spelling of 91893391 in words is "ninety-one million, eight hundred ninety-three thousand, three hundred ninety-one".