78979609 has 2 divisors, whose sum is σ = 78979610. Its totient is φ = 78979608.

The previous prime is 78979601. The next prime is 78979613. The reversal of 78979609 is 90697987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56625625 + 22353984 = 7525^2 + 4728^2 .

It is an emirp because it is prime and its reverse (90697987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78979609 - 2³ = 78979601 is a prime.

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 78979609.

It is not a weakly prime, because it can be changed into another prime (78979601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39489804 + 39489805.

It is an arithmetic number, because the mean of its divisors is an integer number (39489805).

Almost surely, 2^78979609 is an apocalyptic number.

It is an amenable number.

78979609 is a deficient number, since it is larger than the sum of its proper divisors (1).

78979609 is an equidigital number, since it uses as much as digits as its factorization.

78979609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1714608, while the sum is 55.

The square root of 78979609 is about 8887.0472599171. The cubic root of 78979609 is about 429.0471220039.

The spelling of 78979609 in words is "seventy-eight million, nine hundred seventy-nine thousand, six hundred nine".