2561563 has 4 divisors (see below), whose sum is σ = 2564968. Its totient is φ = 2558160.

The previous prime is 2561551. The next prime is 2561593. The reversal of 2561563 is 3651652.

2561563 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2561563 - 2⁹ = 2561051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561513) 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 3 ways as a sum of consecutive naturals, for example, 18 + ... + 2263.

It is an arithmetic number, because the mean of its divisors is an integer number (641242).

2^2561563 is an apocalyptic number.

2561563 is a deficient number, since it is larger than the sum of its proper divisors (3405).

2561563 is a wasteful number, since it uses less digits than its factorization.

2561563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3404.

The product of its digits is 5400, while the sum is 28.

The square root of 2561563 is about 1600.4883629693. The cubic root of 2561563 is about 136.8259106160.

The spelling of 2561563 in words is "two million, five hundred sixty-one thousand, five hundred sixty-three".