2565643 has 2 divisors, whose sum is σ = 2565644. Its totient is φ = 2565642.

The previous prime is 2565611. The next prime is 2565649. The reversal of 2565643 is 3465652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2565643 - 2⁵ = 2565611 is a prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as 2¹⁹ + 5⁷ + 6⁴ + 5⁹ + 6⁵ + 4⁵ + 3² .

2565643 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2565649) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1282821 + 1282822.

It is an arithmetic number, because the mean of its divisors is an integer number (1282822).

2^2565643 is an apocalyptic number.

2565643 is a deficient number, since it is larger than the sum of its proper divisors (1).

2565643 is an equidigital number, since it uses as much as digits as its factorization.

2565643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 31.

The square root of 2565643 is about 1601.7624667846. The cubic root of 2565643 is about 136.8985164934.

Subtracting 2565643 from its reverse (3465652), we obtain a palindrome (900009).

The spelling of 2565643 in words is "two million, five hundred sixty-five thousand, six hundred forty-three".