2565663 has 4 divisors (see below), whose sum is σ = 3420888. Its totient is φ = 1710440.

The previous prime is 2565649. The next prime is 2565671. The reversal of 2565663 is 3665652.

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 2565663 - 2⁹ = 2565151 is a prime.

It is an Ulam number.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565643) 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, 427608 + ... + 427613.

It is an arithmetic number, because the mean of its divisors is an integer number (855222).

2^2565663 is an apocalyptic number.

2565663 is a deficient number, since it is larger than the sum of its proper divisors (855225).

2565663 is an equidigital number, since it uses as much as digits as its factorization.

2565663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855224.

The product of its digits is 32400, while the sum is 33.

The square root of 2565663 is about 1601.7687098954. The cubic root of 2565663 is about 136.8988722150.

The spelling of 2565663 in words is "two million, five hundred sixty-five thousand, six hundred sixty-three".