91799242778879 has 2 divisors, whose sum is σ = 91799242778880. Its totient is φ = 91799242778878.

The previous prime is 91799242778863. The next prime is 91799242778899. The reversal of 91799242778879 is 97887724299719.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (97887724299719) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91799242778879 - 2⁴ = 91799242778863 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91799242778794 and 91799242778803.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91799242778839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45899621389439 + 45899621389440.

It is an arithmetic number, because the mean of its divisors is an integer number (45899621389440).

Almost surely, 2^{91799242778879} is an apocalyptic number.

91799242778879 is a deficient number, since it is larger than the sum of its proper divisors (1).

91799242778879 is an equidigital number, since it uses as much as digits as its factorization.

91799242778879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16131032064, while the sum is 89.

The spelling of 91799242778879 in words is "ninety-one trillion, seven hundred ninety-nine billion, two hundred forty-two million, seven hundred seventy-eight thousand, eight hundred seventy-nine".