2181647789 has 2 divisors, whose sum is σ = 2181647790. Its totient is φ = 2181647788.

The previous prime is 2181647777. The next prime is 2181647801. The reversal of 2181647789 is 9877461812.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (2181647777) and next prime (2181647801).

It can be written as a sum of positive squares in only one way, i.e., 1236577225 + 945070564 = 35165^2 + 30742^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181647789 - 2²⁴ = 2164870573 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2181647789.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2181647729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090823894 + 1090823895.

It is an arithmetic number, because the mean of its divisors is an integer number (1090823895).

Almost surely, 2^2181647789 is an apocalyptic number.

It is an amenable number.

2181647789 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181647789 is an equidigital number, since it uses as much as digits as its factorization.

2181647789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1354752, while the sum is 53.

The square root of 2181647789 is about 46708.1126679295. The cubic root of 2181647789 is about 1296.9648698424.

The spelling of 2181647789 in words is "two billion, one hundred eighty-one million, six hundred forty-seven thousand, seven hundred eighty-nine".