2181687287889 has 16 divisors (see below), whose sum is σ = 3062054810880. Its totient is φ = 1377890856720.

The previous prime is 2181687287839. The next prime is 2181687287893. The reversal of 2181687287889 is 9887827861812.

It is not a de Polignac number, because 2181687287889 - 2¹⁹ = 2181686763601 is a prime.

It is a super-4 number, since 4×2181687287889⁴ (a number of 50 digits) contains 4444 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2181687287889.

It is not an unprimeable number, because it can be changed into a prime (2181687287839) 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, 5801974 + ... + 6166544.

It is an arithmetic number, because the mean of its divisors is an integer number (191378425680).

Almost surely, 2^{2181687287889} is an apocalyptic number.

It is an amenable number.

2181687287889 is a deficient number, since it is larger than the sum of its proper divisors (880367522991).

2181687287889 is a wasteful number, since it uses less digits than its factorization.

2181687287889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469580.

The product of its digits is 346816512, while the sum is 75.

It can be divided in two parts, 218168 and 7287889, that added together give a palindrome (7506057).

The spelling of 2181687287889 in words is "two trillion, one hundred eighty-one billion, six hundred eighty-seven million, two hundred eighty-seven thousand, eight hundred eighty-nine".