866161 has 2 divisors, whose sum is σ = 866162. Its totient is φ = 866160.

The previous prime is 866123. The next prime is 866183. The reversal of 866161 is 161668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 776161 + 90000 = 881^2 + 300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866161 is a prime.

866161 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (866101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433080 + 433081.

It is an arithmetic number, because the mean of its divisors is an integer number (433081).

2⁸⁶⁶¹⁶¹ is an apocalyptic number.

It is an amenable number.

866161 is a deficient number, since it is larger than the sum of its proper divisors (1).

866161 is an equidigital number, since it uses as much as digits as its factorization.

866161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 866161 is about 930.6777100586. The cubic root of 866161 is about 95.3234038050.

The spelling of 866161 in words is "eight hundred sixty-six thousand, one hundred sixty-one".