2565438663 has 4 divisors (see below), whose sum is σ = 3420584888. Its totient is φ = 1710292440.

The previous prime is 2565438619. The next prime is 2565438677. The reversal of 2565438663 is 3668345652.

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

It is not a de Polignac number, because 2565438663 - 2¹⁶ = 2565373127 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 (2565438163) 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, 427573108 + ... + 427573113.

It is an arithmetic number, because the mean of its divisors is an integer number (855146222).

Almost surely, 2^2565438663 is an apocalyptic number.

2565438663 is a deficient number, since it is larger than the sum of its proper divisors (855146225).

2565438663 is an equidigital number, since it uses as much as digits as its factorization.

2565438663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855146224.

The product of its digits is 3110400, while the sum is 48.

The square root of 2565438663 is about 50650.1595555236. The cubic root of 2565438663 is about 1368.9488203419.

The spelling of 2565438663 in words is "two billion, five hundred sixty-five million, four hundred thirty-eight thousand, six hundred sixty-three".