2165740644 has 12 divisors (see below), whose sum is σ = 5053394864. Its totient is φ = 721913544.

The previous prime is 2165740639. The next prime is 2165740657. The reversal of 2165740644 is 4460475612.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90239182 + ... + 90239205.

Almost surely, 2^2165740644 is an apocalyptic number.

It is an amenable number.

2165740644 is an abundant number, since it is smaller than the sum of its proper divisors (2887654220).

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

2165740644 is a wasteful number, since it uses less digits than its factorization.

2165740644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180478394 (or 180478392 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 39.

The square root of 2165740644 is about 46537.5186704233. The cubic root of 2165740644 is about 1293.8049716146.

The spelling of 2165740644 in words is "two billion, one hundred sixty-five million, seven hundred forty thousand, six hundred forty-four".