2564921 has 2 divisors, whose sum is σ = 2564922. Its totient is φ = 2564920.

The previous prime is 2564917. The next prime is 2564957. The reversal of 2564921 is 1294652.

It is a happy number.

2564921 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., 2524921 + 40000 = 1589^2 + 200^2 .

It is a cyclic number.

It is not a de Polignac number, because 2564921 - 2² = 2564917 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2564321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1282460 + 1282461.

It is an arithmetic number, because the mean of its divisors is an integer number (1282461).

2^2564921 is an apocalyptic number.

It is an amenable number.

2564921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2564921 is an equidigital number, since it uses as much as digits as its factorization.

2564921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 29.

The square root of 2564921 is about 1601.5370741884. The cubic root of 2564921 is about 136.8856737087.

It can be divided in two parts, 25 and 64921, that added together give a palindrome (64946).

The spelling of 2564921 in words is "two million, five hundred sixty-four thousand, nine hundred twenty-one".