12768221 has 2 divisors, whose sum is σ = 12768222. Its totient is φ = 12768220.

The previous prime is 12768191. The next prime is 12768227. The reversal of 12768221 is 12286721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9211225 + 3556996 = 3035^2 + 1886^2 .

It is a cyclic number.

It is not a de Polignac number, because 12768221 - 2⁶ = 12768157 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12768227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6384110 + 6384111.

It is an arithmetic number, because the mean of its divisors is an integer number (6384111).

Almost surely, 2^12768221 is an apocalyptic number.

It is an amenable number.

12768221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12768221 is an equidigital number, since it uses as much as digits as its factorization.

12768221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 29.

The square root of 12768221 is about 3573.2647536951. The cubic root of 12768221 is about 233.7276703769.

The spelling of 12768221 in words is "twelve million, seven hundred sixty-eight thousand, two hundred twenty-one".