7978979 has 2 divisors, whose sum is σ = 7978980. Its totient is φ = 7978978.

The previous prime is 7978961. The next prime is 7978981. The reversal of 7978979 is 9798797.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7978979 is a prime.

Together with 7978981, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (7978279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3989489 + 3989490.

It is an arithmetic number, because the mean of its divisors is an integer number (3989490).

Almost surely, 2^7978979 is an apocalyptic number.

7978979 is a deficient number, since it is larger than the sum of its proper divisors (1).

7978979 is an equidigital number, since it uses as much as digits as its factorization.

7978979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2000376, while the sum is 56.

The square root of 7978979 is about 2824.7086575433. The cubic root of 7978979 is about 199.8246713442.

The spelling of 7978979 in words is "seven million, nine hundred seventy-eight thousand, nine hundred seventy-nine".