281916989 has 2 divisors, whose sum is σ = 281916990. Its totient is φ = 281916988.

The previous prime is 281916983. The next prime is 281917037. The reversal of 281916989 is 989619182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 237468100 + 44448889 = 15410^2 + 6667^2 .

It is a cyclic number.

It is not a de Polignac number, because 281916989 - 2¹² = 281912893 is a prime.

It is a super-2 number, since 2×281916989² = 158954377373652242, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 281916989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (281916983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140958494 + 140958495.

It is an arithmetic number, because the mean of its divisors is an integer number (140958495).

Almost surely, 2^281916989 is an apocalyptic number.

It is an amenable number.

281916989 is a deficient number, since it is larger than the sum of its proper divisors (1).

281916989 is an equidigital number, since it uses as much as digits as its factorization.

281916989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 53.

The square root of 281916989 is about 16790.3838252733. The cubic root of 281916989 is about 655.7028672756.

The spelling of 281916989 in words is "two hundred eighty-one million, nine hundred sixteen thousand, nine hundred eighty-nine".