866506 has 4 divisors (see below), whose sum is σ = 1299762. Its totient is φ = 433252.

The previous prime is 866477. The next prime is 866513. The reversal of 866506 is 605668.

866506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 455625 + 410881 = 675^2 + 641^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 216625 + ... + 216628.

2⁸⁶⁶⁵⁰⁶ is an apocalyptic number.

866506 is a deficient number, since it is larger than the sum of its proper divisors (433256).

866506 is a wasteful number, since it uses less digits than its factorization.

866506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433255.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 866506 is about 930.8630404093. The cubic root of 866506 is about 95.3360581917.

The spelling of 866506 in words is "eight hundred sixty-six thousand, five hundred six".