866056500 has 144 divisors (see below), whose sum is σ = 2893088016. Its totient is φ = 217344000.

The previous prime is 866056481. The next prime is 866056501. The reversal of 866056500 is 5650668.

It can be written as a sum of positive squares in 8 ways, for example, as 368409636 + 497646864 = 19194^2 + 22308^2 .

It is a super-2 number, since 2×866056500² = 1500107722384500000, which contains 22 as substring.

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 (866056501) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 70840 + ... + 82160.

It is an arithmetic number, because the mean of its divisors is an integer number (20090889).

Almost surely, 2^866056500 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 866056500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1446544008).

866056500 is an abundant number, since it is smaller than the sum of its proper divisors (2027031516).

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

866056500 is a wasteful number, since it uses less digits than its factorization.

866056500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11363 (or 11348 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 866056500 is about 29428.8378975453. The cubic root of 866056500 is about 953.1957014650.

The spelling of 866056500 in words is "eight hundred sixty-six million, fifty-six thousand, five hundred".