2565885664 has 96 divisors (see below), whose sum is σ = 5405097600. Its totient is φ = 1196912640.

The previous prime is 2565885659. The next prime is 2565885671. The reversal of 2565885664 is 4665885652.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3881494 + ... + 3882154.

It is an arithmetic number, because the mean of its divisors is an integer number (56303100).

Almost surely, 2^2565885664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2565885664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2702548800).

2565885664 is an abundant number, since it is smaller than the sum of its proper divisors (2839211936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2565885664 is a wasteful number, since it uses less digits than its factorization.

2565885664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836 (or 828 counting only the distinct ones).

The product of its digits is 13824000, while the sum is 55.

The square root of 2565885664 is about 50654.5719950332. The cubic root of 2565885664 is about 1369.0283240883.

It can be divided in two parts, 25 and 65885664, that added together give a square (65885689 = 8117²).

The spelling of 2565885664 in words is "two billion, five hundred sixty-five million, eight hundred eighty-five thousand, six hundred sixty-four".