2565899791 has 72 divisors (see below), whose sum is σ = 3425039712. Its totient is φ = 1880236800.

The previous prime is 2565899773. The next prime is 2565899797. The reversal of 2565899791 is 1979985652.

It is not a de Polignac number, because 2565899791 - 2¹³ = 2565891599 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565899797) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 42063901 + ... + 42063961.

It is an arithmetic number, because the mean of its divisors is an integer number (47569996).

Almost surely, 2^2565899791 is an apocalyptic number.

2565899791 is a deficient number, since it is larger than the sum of its proper divisors (859139921).

2565899791 is a wasteful number, since it uses less digits than its factorization.

2565899791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193 (or 149 counting only the distinct ones).

The product of its digits is 12247200, while the sum is 61.

The square root of 2565899791 is about 50654.7114393123. The cubic root of 2565899791 is about 1369.0308365707.

The spelling of 2565899791 in words is "two billion, five hundred sixty-five million, eight hundred ninety-nine thousand, seven hundred ninety-one".