2565540655 has 4 divisors (see below), whose sum is σ = 3078648792. Its totient is φ = 2052432520.

The previous prime is 2565540581. The next prime is 2565540667. The reversal of 2565540655 is 5560455652.

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

It is not a de Polignac number, because 2565540655 - 2²³ = 2557152047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 256554061 + ... + 256554070.

It is an arithmetic number, because the mean of its divisors is an integer number (769662198).

Almost surely, 2^2565540655 is an apocalyptic number.

2565540655 is a deficient number, since it is larger than the sum of its proper divisors (513108137).

2565540655 is an equidigital number, since it uses as much as digits as its factorization.

2565540655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513108136.

The product of its (nonzero) digits is 900000, while the sum is 43.

The square root of 2565540655 is about 50651.1663735397. The cubic root of 2565540655 is about 1368.9669614861.

The spelling of 2565540655 in words is "two billion, five hundred sixty-five million, five hundred forty thousand, six hundred fifty-five".