2565501664 has 24 divisors (see below), whose sum is σ = 5509998648. Its totient is φ = 1166136960.

The previous prime is 2565501643. The next prime is 2565501667. The reversal of 2565501664 is 4661055652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565501667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3643827 + ... + 3644530.

It is an arithmetic number, because the mean of its divisors is an integer number (229583277).

Almost surely, 2^2565501664 is an apocalyptic number.

It is an amenable number.

2565501664 is an abundant number, since it is smaller than the sum of its proper divisors (2944496984).

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

2565501664 is a wasteful number, since it uses less digits than its factorization.

2565501664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7288378 (or 7288370 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 40.

The square root of 2565501664 is about 50650.7814747216. The cubic root of 2565501664 is about 1368.9600262798.

The spelling of 2565501664 in words is "two billion, five hundred sixty-five million, five hundred one thousand, six hundred sixty-four".