859681 has 2 divisors, whose sum is σ = 859682. Its totient is φ = 859680.

The previous prime is 859679. The next prime is 859697. The reversal of 859681 is 186958.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 614656 + 245025 = 784^2 + 495^2 .

It is a cyclic number.

It is not a de Polignac number, because 859681 - 2¹ = 859679 is a prime.

It is a super-2 number, since 2×859681² = 1478102843522, which contains 22 as substring.

Together with 859679, it forms a pair of twin primes.

859681 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 859681.

It is not a weakly prime, because it can be changed into another prime (859601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 429840 + 429841.

It is an arithmetic number, because the mean of its divisors is an integer number (429841).

2⁸⁵⁹⁶⁸¹ is an apocalyptic number.

It is an amenable number.

859681 is a deficient number, since it is larger than the sum of its proper divisors (1).

859681 is an equidigital number, since it uses as much as digits as its factorization.

859681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 37.

The square root of 859681 is about 927.1898403240. The cubic root of 859681 is about 95.0850945771.

It can be divided in two parts, 859 and 681, that added together give a triangular number (1540 = T₅₅).

The spelling of 859681 in words is "eight hundred fifty-nine thousand, six hundred eighty-one".