2165891867244 has 72 divisors (see below), whose sum is σ = 6402533096960. Its totient is φ = 604434936672.

The previous prime is 2165891867207. The next prime is 2165891867267. The reversal of 2165891867244 is 4427681985612.

It is a happy number.

2165891867244 is a `hidden beast` number, since 2 + 1 + 6 + 589 + 1 + 8 + 6 + 7 + 2 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 99928804 + ... + 99950475.

Almost surely, 2^{2165891867244} is an apocalyptic number.

It is an amenable number.

2165891867244 is an abundant number, since it is smaller than the sum of its proper divisors (4236641229716).

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

2165891867244 is a wasteful number, since it uses less digits than its factorization.

2165891867244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199879339 (or 199879334 counting only the distinct ones).

The product of its digits is 46448640, while the sum is 63.

The spelling of 2165891867244 in words is "two trillion, one hundred sixty-five billion, eight hundred ninety-one million, eight hundred sixty-seven thousand, two hundred forty-four".