12656321 has 2 divisors, whose sum is σ = 12656322. Its totient is φ = 12656320.

The previous prime is 12656311. The next prime is 12656323. The reversal of 12656321 is 12365621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6431296 + 6225025 = 2536^2 + 2495^2 .

It is a cyclic number.

It is not a de Polignac number, because 12656321 - 2²² = 8462017 is a prime.

It is a super-2 number, since 2×12656321² = 320364922510082, which contains 22 as substring.

Together with 12656323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12656323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6328160 + 6328161.

It is an arithmetic number, because the mean of its divisors is an integer number (6328161).

Almost surely, 2^12656321 is an apocalyptic number.

It is an amenable number.

12656321 is a deficient number, since it is larger than the sum of its proper divisors (1).

12656321 is an equidigital number, since it uses as much as digits as its factorization.

12656321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 26.

The square root of 12656321 is about 3557.5723464183. The cubic root of 12656321 is about 233.0428737255.

The spelling of 12656321 in words is "twelve million, six hundred fifty-six thousand, three hundred twenty-one".