91242391 has 2 divisors, whose sum is σ = 91242392. Its totient is φ = 91242390.

The previous prime is 91242377. The next prime is 91242421. The reversal of 91242391 is 19324219.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91242391 - 2⁹ = 91241879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91242341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45621195 + 45621196.

It is an arithmetic number, because the mean of its divisors is an integer number (45621196).

Almost surely, 2^91242391 is an apocalyptic number.

91242391 is a deficient number, since it is larger than the sum of its proper divisors (1).

91242391 is an equidigital number, since it uses as much as digits as its factorization.

91242391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 31.

The square root of 91242391 is about 9552.0883057057. The cubic root of 91242391 is about 450.1931532950.

The spelling of 91242391 in words is "ninety-one million, two hundred forty-two thousand, three hundred ninety-one".