91423879 has 2 divisors, whose sum is σ = 91423880. Its totient is φ = 91423878.

The previous prime is 91423861. The next prime is 91423897. The reversal of 91423879 is 97832419.

Together with next prime (91423897) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (91423861) and next prime (91423897).

It is an emirp because it is prime and its reverse (97832419) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91423879 - 2¹¹ = 91421831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91423279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45711939 + 45711940.

It is an arithmetic number, because the mean of its divisors is an integer number (45711940).

Almost surely, 2^91423879 is an apocalyptic number.

91423879 is a deficient number, since it is larger than the sum of its proper divisors (1).

91423879 is an equidigital number, since it uses as much as digits as its factorization.

91423879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 43.

The square root of 91423879 is about 9561.5834985634. The cubic root of 91423879 is about 450.4914449906.

The spelling of 91423879 in words is "ninety-one million, four hundred twenty-three thousand, eight hundred seventy-nine".