2644646665 has 16 divisors (see below), whose sum is σ = 3200682240. Its totient is φ = 2097688320.

The previous prime is 2644646663. The next prime is 2644646671. The reversal of 2644646665 is 5666464462.

It is not a de Polignac number, because 2644646665 - 2¹ = 2644646663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2644646663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 631057 + ... + 635233.

It is an arithmetic number, because the mean of its divisors is an integer number (200042640).

Almost surely, 2^2644646665 is an apocalyptic number.

It is an amenable number.

2644646665 is a deficient number, since it is larger than the sum of its proper divisors (556035575).

2644646665 is a wasteful number, since it uses less digits than its factorization.

2644646665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5232.

The product of its digits is 4976640, while the sum is 49.

The square root of 2644646665 is about 51426.1282326407. The cubic root of 2644646665 is about 1382.8950399661.

The spelling of 2644646665 in words is "two billion, six hundred forty-four million, six hundred forty-six thousand, six hundred sixty-five".