2181687287893 has 2 divisors, whose sum is σ = 2181687287894. Its totient is φ = 2181687287892.

The previous prime is 2181687287839. The next prime is 2181687287957. The reversal of 2181687287893 is 3987827861812.

It is a happy number.

Together with previous prime (2181687287839) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1688850995364 + 492836292529 = 1299558^2 + 702023^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2181687287893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2181687887893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090843643946 + 1090843643947.

It is an arithmetic number, because the mean of its divisors is an integer number (1090843643947).

Almost surely, 2^{2181687287893} is an apocalyptic number.

It is an amenable number.

2181687287893 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181687287893 is an equidigital number, since it uses as much as digits as its factorization.

2181687287893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 130056192, while the sum is 70.

The spelling of 2181687287893 in words is "two trillion, one hundred eighty-one billion, six hundred eighty-seven million, two hundred eighty-seven thousand, eight hundred ninety-three".