2564643 has 4 divisors (see below), whose sum is σ = 3419528. Its totient is φ = 1709760.

The previous prime is 2564633. The next prime is 2564651. The reversal of 2564643 is 3464652.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 2564643 - 2⁶ = 2564579 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2564643.

It is not an unprimeable number, because it can be changed into a prime (2564633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 427438 + ... + 427443.

It is an arithmetic number, because the mean of its divisors is an integer number (854882).

2^2564643 is an apocalyptic number.

2564643 is a deficient number, since it is larger than the sum of its proper divisors (854885).

2564643 is an equidigital number, since it uses as much as digits as its factorization.

2564643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 854884.

The product of its digits is 17280, while the sum is 30.

The square root of 2564643 is about 1601.4502802148. The cubic root of 2564643 is about 136.8807280604.

Subtracting 2564643 from its reverse (3464652), we obtain a palindrome (900009).

The spelling of 2564643 in words is "two million, five hundred sixty-four thousand, six hundred forty-three".