78439679 has 2 divisors, whose sum is σ = 78439680. Its totient is φ = 78439678.

The previous prime is 78439661. The next prime is 78439681. The reversal of 78439679 is 97693487.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78439679 - 2⁸ = 78439423 is a prime.

Together with 78439681, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78439679.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78439079) 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, 39219839 + 39219840.

It is an arithmetic number, because the mean of its divisors is an integer number (39219840).

Almost surely, 2^78439679 is an apocalyptic number.

78439679 is a deficient number, since it is larger than the sum of its proper divisors (1).

78439679 is an equidigital number, since it uses as much as digits as its factorization.

78439679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2286144, while the sum is 53.

The square root of 78439679 is about 8856.6178081703. The cubic root of 78439679 is about 428.0671841865.

The spelling of 78439679 in words is "seventy-eight million, four hundred thirty-nine thousand, six hundred seventy-nine".