2565454561 has 4 divisors (see below), whose sum is σ = 2566446532. Its totient is φ = 2564462592.

The previous prime is 2565454531. The next prime is 2565454571. The reversal of 2565454561 is 1654545652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1725903936 + 839550625 = 41544^2 + 28975^2 .

It is a cyclic number.

It is not a de Polignac number, because 2565454561 - 2⁹ = 2565454049 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2565454511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 492096 + ... + 497281.

It is an arithmetic number, because the mean of its divisors is an integer number (641611633).

Almost surely, 2^2565454561 is an apocalyptic number.

It is an amenable number.

2565454561 is a deficient number, since it is larger than the sum of its proper divisors (991971).

2565454561 is an equidigital number, since it uses as much as digits as its factorization.

2565454561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991970.

The product of its digits is 720000, while the sum is 43.

The square root of 2565454561 is about 50650.3164945689. The cubic root of 2565454561 is about 1368.9516481239.

The spelling of 2565454561 in words is "two billion, five hundred sixty-five million, four hundred fifty-four thousand, five hundred sixty-one".