78875789 has 2 divisors, whose sum is σ = 78875790. Its totient is φ = 78875788.

The previous prime is 78875773. The next prime is 78875807. The reversal of 78875789 is 98757887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58400164 + 20475625 = 7642^2 + 4525^2 .

It is a cyclic number.

It is not a de Polignac number, because 78875789 - 2⁴ = 78875773 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78875089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39437894 + 39437895.

It is an arithmetic number, because the mean of its divisors is an integer number (39437895).

Almost surely, 2^78875789 is an apocalyptic number.

It is an amenable number.

78875789 is a deficient number, since it is larger than the sum of its proper divisors (1).

78875789 is an equidigital number, since it uses as much as digits as its factorization.

78875789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7902720, while the sum is 59.

The square root of 78875789 is about 8881.2042539286. The cubic root of 78875789 is about 428.8590430603.

The spelling of 78875789 in words is "seventy-eight million, eight hundred seventy-five thousand, seven hundred eighty-nine".