12778565 has 8 divisors (see below), whose sum is σ = 15623928. Its totient is φ = 10029760.

The previous prime is 12778561. The next prime is 12778627. The reversal of 12778565 is 56587721.

12778565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 261121 + 12517444 = 511^2 + 3538^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12778565 - 2² = 12778561 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12778561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23846 + ... + 24375.

It is an arithmetic number, because the mean of its divisors is an integer number (1952991).

Almost surely, 2^12778565 is an apocalyptic number.

It is an amenable number.

12778565 is a deficient number, since it is larger than the sum of its proper divisors (2845363).

12778565 is an equidigital number, since it uses as much as digits as its factorization.

12778565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48279.

The product of its digits is 117600, while the sum is 41.

The square root of 12778565 is about 3574.7118765014. The cubic root of 12778565 is about 233.7907704343.

The spelling of 12778565 in words is "twelve million, seven hundred seventy-eight thousand, five hundred sixty-five".