7899979 has 2 divisors, whose sum is σ = 7899980. Its totient is φ = 7899978.

The previous prime is 7899967. The next prime is 7899989. The reversal of 7899979 is 9799987.

It is a strong prime.

It is an emirp because it is prime and its reverse (9799987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7899979 - 2⁷ = 7899851 is a prime.

It is not a weakly prime, because it can be changed into another prime (7899929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3949989 + 3949990.

It is an arithmetic number, because the mean of its divisors is an integer number (3949990).

Almost surely, 2^7899979 is an apocalyptic number.

7899979 is a deficient number, since it is larger than the sum of its proper divisors (1).

7899979 is an equidigital number, since it uses as much as digits as its factorization.

7899979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2571912, while the sum is 58.

The square root of 7899979 is about 2810.6901287762. The cubic root of 7899979 is about 199.1629936551.

The spelling of 7899979 in words is "seven million, eight hundred ninety-nine thousand, nine hundred seventy-nine".