91985279 has 2 divisors, whose sum is σ = 91985280. Its totient is φ = 91985278.

The previous prime is 91985273. The next prime is 91985291. The reversal of 91985279 is 97258919.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91985279 is a prime.

It is a super-2 number, since 2×91985279² = 16922583105415682, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91985273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45992639 + 45992640.

It is an arithmetic number, because the mean of its divisors is an integer number (45992640).

Almost surely, 2^91985279 is an apocalyptic number.

91985279 is a deficient number, since it is larger than the sum of its proper divisors (1).

91985279 is an equidigital number, since it uses as much as digits as its factorization.

91985279 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 408240, while the sum is 50.

The square root of 91985279 is about 9590.8956307532. The cubic root of 91985279 is about 451.4116640544.

The spelling of 91985279 in words is "ninety-one million, nine hundred eighty-five thousand, two hundred seventy-nine".