2565561 has 4 divisors (see below), whose sum is σ = 3420752. Its totient is φ = 1710372.

The previous prime is 2565559. The next prime is 2565569. The reversal of 2565561 is 1655652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2565561 - 2¹ = 2565559 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2565569) 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, 427591 + ... + 427596.

It is an arithmetic number, because the mean of its divisors is an integer number (855188).

2^2565561 is an apocalyptic number.

It is an amenable number.

2565561 is a deficient number, since it is larger than the sum of its proper divisors (855191).

2565561 is an equidigital number, since it uses as much as digits as its factorization.

2565561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855190.

The product of its digits is 9000, while the sum is 30.

The square root of 2565561 is about 1601.7368697761. The cubic root of 2565561 is about 136.8970580159.

Subtracting from 2565561 its reverse (1655652), we obtain a palindrome (909909).

The spelling of 2565561 in words is "two million, five hundred sixty-five thousand, five hundred sixty-one".