2565118609 has 3 divisors (see below), whose sum is σ = 2565169257. Its totient is φ = 2565067962.

The previous prime is 2565118583. The next prime is 2565118639. The reversal of 2565118609 is 9068115652.

The square root of 2565118609 is 50647.

It is a perfect power (a square), and thus also a powerful number.

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 not a de Polignac number, because 2565118609 - 2⁹ = 2565118097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2565118639) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 25324 + ... + 75970.

It is an arithmetic number, because the mean of its divisors is an integer number (855056419).

Almost surely, 2^2565118609 is an apocalyptic number.

2565118609 is the 50647-th square number.

2565118609 is the 25324-th centered octagonal number.

It is an amenable number.

2565118609 is a deficient number, since it is larger than the sum of its proper divisors (50648).

2565118609 is an frugal number, since it uses more digits than its factorization.

2565118609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101294 (or 50647 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 43.

The cubic root of 2565118609 is about 1368.8918897575.

Multiplying 2565118609 by its product of nonzero digits (129600), we get a square (332439371726400 = 18232920²).

The spelling of 2565118609 in words is "two billion, five hundred sixty-five million, one hundred eighteen thousand, six hundred nine".