91423861 has 2 divisors, whose sum is σ = 91423862. Its totient is φ = 91423860.

The previous prime is 91423853. The next prime is 91423879. The reversal of 91423861 is 16832419.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84824100 + 6599761 = 9210^2 + 2569^2 .

It is a cyclic number.

It is not a de Polignac number, because 91423861 - 2³ = 91423853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91423831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45711930 + 45711931.

It is an arithmetic number, because the mean of its divisors is an integer number (45711931).

Almost surely, 2^91423861 is an apocalyptic number.

It is an amenable number.

91423861 is a deficient number, since it is larger than the sum of its proper divisors (1).

91423861 is an equidigital number, since it uses as much as digits as its factorization.

91423861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 34.

The square root of 91423861 is about 9561.5825572967. The cubic root of 91423861 is about 450.4914154255.

The spelling of 91423861 in words is "ninety-one million, four hundred twenty-three thousand, eight hundred sixty-one".