866851 has 2 divisors, whose sum is σ = 866852. Its totient is φ = 866850.

The previous prime is 866849. The next prime is 866857. The reversal of 866851 is 158668.

It is a happy number.

866851 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 866851 - 2¹ = 866849 is a prime.

Together with 866849, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (866857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433425 + 433426.

It is an arithmetic number, because the mean of its divisors is an integer number (433426).

2⁸⁶⁶⁸⁵¹ is an apocalyptic number.

866851 is a deficient number, since it is larger than the sum of its proper divisors (1).

866851 is an equidigital number, since it uses as much as digits as its factorization.

866851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 34.

The square root of 866851 is about 931.0483338689. The cubic root of 866851 is about 95.3487092201.

The spelling of 866851 in words is "eight hundred sixty-six thousand, eight hundred fifty-one".