12778209 has 16 divisors (see below), whose sum is σ = 19443840. Its totient is φ = 8287920.

The previous prime is 12778201. The next prime is 12778229. The reversal of 12778209 is 90287721.

It is not a de Polignac number, because 12778209 - 2³ = 12778201 is a prime.

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

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5397 + ... + 7394.

It is an arithmetic number, because the mean of its divisors is an integer number (1215240).

Almost surely, 2^12778209 is an apocalyptic number.

It is an amenable number.

12778209 is a deficient number, since it is larger than the sum of its proper divisors (6665631).

12778209 is a wasteful number, since it uses less digits than its factorization.

12778209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12837 (or 12831 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 12778209 is about 3574.6620819317. The cubic root of 12778209 is about 233.7885993432.

The spelling of 12778209 in words is "twelve million, seven hundred seventy-eight thousand, two hundred nine".