999987281 has 2 divisors, whose sum is σ = 999987282. Its totient is φ = 999987280.

The previous prime is 999987227. The next prime is 999987299. The reversal of 999987281 is 182789999.

999987281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 985394881 + 14592400 = 31391^2 + 3820^2 .

It is a cyclic number.

It is not a de Polignac number, because 999987281 - 2²² = 995792977 is a prime.

It is a super-2 number, since 2×999987281² = 1999949124323545922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (999987211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499993640 + 499993641.

It is an arithmetic number, because the mean of its divisors is an integer number (499993641).

Almost surely, 2^999987281 is an apocalyptic number.

It is an amenable number.

999987281 is a deficient number, since it is larger than the sum of its proper divisors (1).

999987281 is an equidigital number, since it uses as much as digits as its factorization.

999987281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5878656, while the sum is 62.

The square root of 999987281 is about 31622.5754959965. The cubic root of 999987281 is about 999.9957603154.

The spelling of 999987281 in words is "nine hundred ninety-nine million, nine hundred eighty-seven thousand, two hundred eighty-one".