78561089 has 2 divisors, whose sum is σ = 78561090. Its totient is φ = 78561088.

The previous prime is 78561079. The next prime is 78561151. The reversal of 78561089 is 98016587.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75550864 + 3010225 = 8692^2 + 1735^2 .

It is a cyclic number.

It is not a de Polignac number, because 78561089 - 2¹⁶ = 78495553 is a prime.

It is not a weakly prime, because it can be changed into another prime (78561019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39280544 + 39280545.

It is an arithmetic number, because the mean of its divisors is an integer number (39280545).

Almost surely, 2^78561089 is an apocalyptic number.

It is an amenable number.

78561089 is a deficient number, since it is larger than the sum of its proper divisors (1).

78561089 is an equidigital number, since it uses as much as digits as its factorization.

78561089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 78561089 is about 8863.4693546038. The cubic root of 78561089 is about 428.2879264027.

The spelling of 78561089 in words is "seventy-eight million, five hundred sixty-one thousand, eighty-nine".