12778205 has 12 divisors (see below), whose sum is σ = 16855356. Its totient is φ = 9292800.

The previous prime is 12778201. The next prime is 12778229. The reversal of 12778205 is 50287721.

12778205 is digitally balanced in base 3, 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 2 ways, for example, as 7027801 + 5750404 = 2651^2 + 2398^2 .

It is not a de Polignac number, because 12778205 - 2² = 12778201 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12778201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9956 + ... + 11165.

It is an arithmetic number, because the mean of its divisors is an integer number (1404613).

Almost surely, 2^12778205 is an apocalyptic number.

It is an amenable number.

12778205 is a deficient number, since it is larger than the sum of its proper divisors (4077151).

12778205 is a wasteful number, since it uses less digits than its factorization.

12778205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21148 (or 21137 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 12778205 is about 3574.6615224382. The cubic root of 12778205 is about 233.7885749486.

The spelling of 12778205 in words is "twelve million, seven hundred seventy-eight thousand, two hundred five".