866081 has 2 divisors, whose sum is σ = 866082. Its totient is φ = 866080.

The previous prime is 866057. The next prime is 866083. The reversal of 866081 is 180668.

866081 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., 654481 + 211600 = 809^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 866081 - 2¹⁰ = 865057 is a prime.

It is a super-2 number, since 2×866081² = 1500192597122, which contains 22 as substring.

Together with 866083, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (866083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433040 + 433041.

It is an arithmetic number, because the mean of its divisors is an integer number (433041).

2⁸⁶⁶⁰⁸¹ is an apocalyptic number.

It is an amenable number.

866081 is a deficient number, since it is larger than the sum of its proper divisors (1).

866081 is an equidigital number, since it uses as much as digits as its factorization.

866081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 866081 is about 930.6347296335. The cubic root of 866081 is about 95.3204689745.

The spelling of 866081 in words is "eight hundred sixty-six thousand, eighty-one".