78905089 has 2 divisors, whose sum is σ = 78905090. Its totient is φ = 78905088.

The previous prime is 78905077. The next prime is 78905131. The reversal of 78905089 is 98050987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67568400 + 11336689 = 8220^2 + 3367^2 .

It is an emirp because it is prime and its reverse (98050987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78905089 - 2⁹ = 78904577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78905009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39452544 + 39452545.

It is an arithmetic number, because the mean of its divisors is an integer number (39452545).

Almost surely, 2^78905089 is an apocalyptic number.

It is an amenable number.

78905089 is a deficient number, since it is larger than the sum of its proper divisors (1).

78905089 is an equidigital number, since it uses as much as digits as its factorization.

78905089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 46.

The square root of 78905089 is about 8882.8536518396. The cubic root of 78905089 is about 428.9121392618.

The spelling of 78905089 in words is "seventy-eight million, nine hundred five thousand, eighty-nine".