866983895844 has 72 divisors (see below), whose sum is σ = 2226582281280. Its totient is φ = 262368469440.

The previous prime is 866983895837. The next prime is 866983895887. The reversal of 866983895844 is 448598389668.

It is a happy number.

It is a super-2 number, since 2×866983895844² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 866983895844.

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 23 ways as a sum of consecutive naturals, for example, 677022 + ... + 1480650.

Almost surely, 2^866983895844 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 866983895844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1113291140640).

866983895844 is an abundant number, since it is smaller than the sum of its proper divisors (1359598385436).

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

866983895844 is a wasteful number, since it uses less digits than its factorization.

866983895844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804401 (or 804388 counting only the distinct ones).

The product of its digits is 2866544640, while the sum is 78.

The spelling of 866983895844 in words is "eight hundred sixty-six billion, nine hundred eighty-three million, eight hundred ninety-five thousand, eight hundred forty-four".