12778817 has 2 divisors, whose sum is σ = 12778818. Its totient is φ = 12778816.

The previous prime is 12778813. The next prime is 12778853. The reversal of 12778817 is 71887721.

12778817 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9096256 + 3682561 = 3016^2 + 1919^2 .

It is an emirp because it is prime and its reverse (71887721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12778817 - 2² = 12778813 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12778813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6389408 + 6389409.

It is an arithmetic number, because the mean of its divisors is an integer number (6389409).

Almost surely, 2^12778817 is an apocalyptic number.

It is an amenable number.

12778817 is a deficient number, since it is larger than the sum of its proper divisors (1).

12778817 is an equidigital number, since it uses as much as digits as its factorization.

12778817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43904, while the sum is 41.

The square root of 12778817 is about 3574.7471239236. The cubic root of 12778817 is about 233.7923072497.

The spelling of 12778817 in words is "twelve million, seven hundred seventy-eight thousand, eight hundred seventeen".