866580120 has 320 divisors, whose sum is σ = 3505708800. Its totient is φ = 187557120.

The previous prime is 866580119. The next prime is 866580137. The reversal of 866580120 is 21085668.

It is a happy number.

866580120 is a `hidden beast` number, since 8 + 66 + 580 + 12 + 0 = 666.

It is a super-2 number, since 2×866580120² = 1501922208758428800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 9.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 429915 + ... + 431925.

It is an arithmetic number, because the mean of its divisors is an integer number (10955340).

Almost surely, 2^866580120 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 866580120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1752854400).

866580120 is an abundant number, since it is smaller than the sum of its proper divisors (2639128680).

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

866580120 is a wasteful number, since it uses less digits than its factorization.

866580120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2060 (or 2047 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 866580120 is about 29437.7329290148. The cubic root of 866580120 is about 953.3877642918.

The spelling of 866580120 in words is "eight hundred sixty-six million, five hundred eighty thousand, one hundred twenty".