78445896209 has 4 divisors (see below), whose sum is σ = 80566055604. Its totient is φ = 76325736816.

The previous prime is 78445896169. The next prime is 78445896241. The reversal of 78445896209 is 90269854487.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 66617158609 + 11828737600 = 258103^2 + 108760^2 .

It is a cyclic number.

It is not a de Polignac number, because 78445896209 - 2⁸ = 78445895953 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78445890209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060079642 + ... + 1060079715.

It is an arithmetic number, because the mean of its divisors is an integer number (20141513901).

Almost surely, 2^78445896209 is an apocalyptic number.

It is an amenable number.

78445896209 is a deficient number, since it is larger than the sum of its proper divisors (2120159395).

78445896209 is a wasteful number, since it uses less digits than its factorization.

78445896209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120159394.

The product of its (nonzero) digits is 34836480, while the sum is 62.

The spelling of 78445896209 in words is "seventy-eight billion, four hundred forty-five million, eight hundred ninety-six thousand, two hundred nine".