99779879 has 2 divisors, whose sum is σ = 99779880. Its totient is φ = 99779878.

The previous prime is 99779873. The next prime is 99779881. The reversal of 99779879 is 97897799.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99779879 is a prime.

Together with 99779881, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99779873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49889939 + 49889940.

It is an arithmetic number, because the mean of its divisors is an integer number (49889940).

Almost surely, 2^99779879 is an apocalyptic number.

99779879 is a deficient number, since it is larger than the sum of its proper divisors (1).

99779879 is an equidigital number, since it uses as much as digits as its factorization.

99779879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18003384, while the sum is 65.

The square root of 99779879 is about 9988.9878866680. The cubic root of 99779879 is about 463.8180627744.

The spelling of 99779879 in words is "ninety-nine million, seven hundred seventy-nine thousand, eight hundred seventy-nine".