985781 has 2 divisors, whose sum is σ = 985782. Its totient is φ = 985780.

The previous prime is 985759. The next prime is 985783. The reversal of 985781 is 187589.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 874225 + 111556 = 935^2 + 334^2 .

It is a cyclic number.

It is not a de Polignac number, because 985781 - 2¹⁰ = 984757 is a prime.

It is a super-2 number, since 2×985781² = 1943528359922, which contains 22 as substring.

Together with 985783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (985783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 492890 + 492891.

It is an arithmetic number, because the mean of its divisors is an integer number (492891).

2⁹⁸⁵⁷⁸¹ is an apocalyptic number.

It is an amenable number.

985781 is a deficient number, since it is larger than the sum of its proper divisors (1).

985781 is an equidigital number, since it uses as much as digits as its factorization.

985781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 38.

The square root of 985781 is about 992.8650462173. The cubic root of 985781 is about 99.5237689737.

The spelling of 985781 in words is "nine hundred eighty-five thousand, seven hundred eighty-one".