866140 has 48 divisors (see below), whose sum is σ = 2064384. Its totient is φ = 302400.

The previous prime is 866123. The next prime is 866161. The reversal of 866140 is 41668.

866140 = 11² + 12² + ... + 137².

It is a Smith number, since the sum of its digits (25) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6757 + ... + 6883.

It is an arithmetic number, because the mean of its divisors is an integer number (43008).

2⁸⁶⁶¹⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1032192).

866140 is an abundant number, since it is smaller than the sum of its proper divisors (1198244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866140 is a wasteful number, since it uses less digits than its factorization.

866140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 866140 is about 930.6664278892. Note that the first 3 decimals coincide. The cubic root of 866140 is about 95.3226334294.

It can be divided in two parts, 86 and 6140, that added together give a palindrome (6226).

The spelling of 866140 in words is "eight hundred sixty-six thousand, one hundred forty".