2561567 has 4 divisors (see below), whose sum is σ = 2568240. Its totient is φ = 2554896.

The previous prime is 2561551. The next prime is 2561593. The reversal of 2561567 is 7651652.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2561567 - 2⁴ = 2561551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561527) 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, 2723 + ... + 3540.

It is an arithmetic number, because the mean of its divisors is an integer number (642060).

2^2561567 is an apocalyptic number.

2561567 is a deficient number, since it is larger than the sum of its proper divisors (6673).

2561567 is an equidigital number, since it uses as much as digits as its factorization.

2561567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6672.

The product of its digits is 12600, while the sum is 32.

The square root of 2561567 is about 1600.4896125873. The cubic root of 2561567 is about 136.8259818359.

The spelling of 2561567 in words is "two million, five hundred sixty-one thousand, five hundred sixty-seven".