866256120 has 224 divisors, whose sum is σ = 2976282720. Its totient is φ = 226748160.

The previous prime is 866256119. The next prime is 866256121. The reversal of 866256120 is 21652668.

866256120 is a `hidden beast` number, since 8 + 6 + 625 + 6 + 1 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (866256119) and next prime (866256121).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866256121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 1778517 + ... + 1779003.

Almost surely, 2^866256120 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 866256120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1488141360).

866256120 is an abundant number, since it is smaller than the sum of its proper divisors (2110026600).

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

866256120 is a wasteful number, since it uses less digits than its factorization.

866256120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 866256120 is about 29432.2292733663. The cubic root of 866256120 is about 953.2689308323.

The spelling of 866256120 in words is "eight hundred sixty-six million, two hundred fifty-six thousand, one hundred twenty".