2565844491 has 8 divisors (see below), whose sum is σ = 3909858304. Its totient is φ = 1466196840.

The previous prime is 2565844471. The next prime is 2565844499. The reversal of 2565844491 is 1944485652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2565844491 - 2¹⁵ = 2565811723 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2565844491.

It is not an unprimeable number, because it can be changed into a prime (2565844499) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61091515 + ... + 61091556.

It is an arithmetic number, because the mean of its divisors is an integer number (488732288).

Almost surely, 2^2565844491 is an apocalyptic number.

2565844491 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2565844491 is a deficient number, since it is larger than the sum of its proper divisors (1344013813).

2565844491 is a wasteful number, since it uses less digits than its factorization.

2565844491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122183081.

The product of its digits is 1382400, while the sum is 48.

The square root of 2565844491 is about 50654.1655838886. The cubic root of 2565844491 is about 1369.0210014310.

The spelling of 2565844491 in words is "two billion, five hundred sixty-five million, eight hundred forty-four thousand, four hundred ninety-one".