2564639 has 16 divisors (see below), whose sum is σ = 3367680. Its totient is φ = 1892160.

The previous prime is 2564633. The next prime is 2564651. The reversal of 2564639 is 9364652.

2564639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 2564639 - 2¹² = 2560543 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a d-powerful number, because it can be written as 2¹¹ + 5⁹ + 6⁴ + 4⁷ + 6⁴ + 3¹² + 9⁵ .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2564599 and 2564608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2564633) 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 in 15 ways as a sum of consecutive naturals, for example, 587 + ... + 2339.

It is an arithmetic number, because the mean of its divisors is an integer number (210480).

2^2564639 is an apocalyptic number.

2564639 is a deficient number, since it is larger than the sum of its proper divisors (803041).

2564639 is a wasteful number, since it uses less digits than its factorization.

2564639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1790.

The product of its digits is 38880, while the sum is 35.

The square root of 2564639 is about 1601.4490313463. The cubic root of 2564639 is about 136.8806568973.

The spelling of 2564639 in words is "two million, five hundred sixty-four thousand, six hundred thirty-nine".