2564321 has 2 divisors, whose sum is σ = 2564322. Its totient is φ = 2564320.

The previous prime is 2564279. The next prime is 2564323. The reversal of 2564321 is 1234652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2371600 + 192721 = 1540^2 + 439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2564321 is a prime.

Together with 2564323, 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 (2564323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1282160 + 1282161.

It is an arithmetic number, because the mean of its divisors is an integer number (1282161).

2^2564321 is an apocalyptic number.

It is an amenable number.

2564321 is a deficient number, since it is larger than the sum of its proper divisors (1).

2564321 is an equidigital number, since it uses as much as digits as its factorization.

2564321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 23.

The square root of 2564321 is about 1601.3497431854. The cubic root of 2564321 is about 136.8749992007.

Adding to 2564321 its reverse (1234652), we get a palindrome (3798973).

It can be divided in two parts, 25 and 64321, that added together give a palindrome (64346).

The spelling of 2564321 in words is "two million, five hundred sixty-four thousand, three hundred twenty-one".