78966689 has 2 divisors, whose sum is σ = 78966690. Its totient is φ = 78966688.

The previous prime is 78966677. The next prime is 78966709. The reversal of 78966689 is 98666987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72165025 + 6801664 = 8495^2 + 2608^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78966689 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (78966089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39483344 + 39483345.

It is an arithmetic number, because the mean of its divisors is an integer number (39483345).

Almost surely, 2^78966689 is an apocalyptic number.

It is an amenable number.

78966689 is a deficient number, since it is larger than the sum of its proper divisors (1).

78966689 is an equidigital number, since it uses as much as digits as its factorization.

78966689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 59.

The square root of 78966689 is about 8886.3203295852. The cubic root of 78966689 is about 429.0237252850.

The spelling of 78966689 in words is "seventy-eight million, nine hundred sixty-six thousand, six hundred eighty-nine".