281866889 has 2 divisors, whose sum is σ = 281866890. Its totient is φ = 281866888.

The previous prime is 281866853. The next prime is 281866891. The reversal of 281866889 is 988668182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 247527289 + 34339600 = 15733^2 + 5860^2 .

It is a cyclic number.

It is not a de Polignac number, because 281866889 - 2²⁴ = 265089673 is a prime.

It is a super-2 number, since 2×281866889² = 158897886229076642, which contains 22 as substring.

Together with 281866891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (281868889) 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, 140933444 + 140933445.

It is an arithmetic number, because the mean of its divisors is an integer number (140933445).

Almost surely, 2^281866889 is an apocalyptic number.

It is an amenable number.

281866889 is a deficient number, since it is larger than the sum of its proper divisors (1).

281866889 is an equidigital number, since it uses as much as digits as its factorization.

281866889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2654208, while the sum is 56.

The square root of 281866889 is about 16788.8918335904. The cubic root of 281866889 is about 655.6640229099.

The spelling of 281866889 in words is "two hundred eighty-one million, eight hundred sixty-six thousand, eight hundred eighty-nine".