866159 has 4 divisors (see below), whose sum is σ = 989904. Its totient is φ = 742416.

The previous prime is 866123. The next prime is 866161. The reversal of 866159 is 951668.

866159 = 193² + 194² + ... + 213².

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 866159 - 2¹⁶ = 800623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61862 + ... + 61875.

It is an arithmetic number, because the mean of its divisors is an integer number (247476).

2⁸⁶⁶¹⁵⁹ is an apocalyptic number.

866159 is a deficient number, since it is larger than the sum of its proper divisors (123745).

866159 is a wasteful number, since it uses less digits than its factorization.

866159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123744.

The product of its digits is 12960, while the sum is 35.

The square root of 866159 is about 930.6766355722. The cubic root of 866159 is about 95.3233304364.

The spelling of 866159 in words is "eight hundred sixty-six thousand, one hundred fifty-nine".