866320 has 120 divisors (see below), whose sum is σ = 2671704. Its totient is φ = 258048.

The previous prime is 866311. The next prime is 866329. The reversal of 866320 is 23668.

It is an interprime number because it is at equal distance from previous prime (866311) and next prime (866329).

It can be written as a sum of positive squares in 4 ways, for example, as 63504 + 802816 = 252^2 + 896^2 .

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866329) by changing a digit.

866320 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 (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50952 + ... + 50968.

2⁸⁶⁶³²⁰ is an apocalyptic number.

866320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1335852).

866320 is an abundant number, since it is smaller than the sum of its proper divisors (1805384).

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

866320 is a wasteful number, since it uses less digits than its factorization.

866320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 866320 is about 930.7631277613. The cubic root of 866320 is about 95.3292362441.

Adding to 866320 its reverse (23668), we get a palindrome (889988).

The spelling of 866320 in words is "eight hundred sixty-six thousand, three hundred twenty".