866540 has 24 divisors (see below), whose sum is σ = 1870512. Its totient is φ = 336960.

The previous prime is 866519. The next prime is 866573. The reversal of 866540 is 45668.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a plaindrome in base 13.

It is a nialpdrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 866540.

It is an unprimeable number.

866540 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155 + ... + 1325.

It is an arithmetic number, because the mean of its divisors is an integer number (77938).

2⁸⁶⁶⁵⁴⁰ 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 866540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (935256).

866540 is an abundant number, since it is smaller than the sum of its proper divisors (1003972).

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

866540 is a wasteful number, since it uses less digits than its factorization.

866540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217 (or 1215 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 866540 is about 930.8813028523. The cubic root of 866540 is about 95.3373051089.

The spelling of 866540 in words is "eight hundred sixty-six thousand, five hundred forty".