99997879 has 2 divisors, whose sum is σ = 99997880. Its totient is φ = 99997878.

The previous prime is 99997873. The next prime is 99997897. The reversal of 99997879 is 97879999.

Together with next prime (99997897) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99997879 - 2³ = 99997871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99997871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49998939 + 49998940.

It is an arithmetic number, because the mean of its divisors is an integer number (49998940).

Almost surely, 2^99997879 is an apocalyptic number.

99997879 is a deficient number, since it is larger than the sum of its proper divisors (1).

99997879 is an equidigital number, since it uses as much as digits as its factorization.

99997879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23147208, while the sum is 67.

The square root of 99997879 is about 9999.8939494377. The cubic root of 99997879 is about 464.1556017348.

The spelling of 99997879 in words is "ninety-nine million, nine hundred ninety-seven thousand, eight hundred seventy-nine".