866836638668 has 96 divisors (see below), whose sum is σ = 2037331752960. Its totient is φ = 311662391040.

The previous prime is 866836638659. The next prime is 866836638673.

It is a happy number.

866836638668 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 866836638595 and 866836638604.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15278978 + ... + 15335606.

It is an arithmetic number, because the mean of its divisors is an integer number (21222205760).

Almost surely, 2^866836638668 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 866836638668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1018665876480).

866836638668 is an abundant number, since it is smaller than the sum of its proper divisors (1170495114292).

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

866836638668 is a wasteful number, since it uses less digits than its factorization.

866836638668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60487 (or 60485 counting only the distinct ones).

The product of its digits is 1719926784, while the sum is 74.

The spelling of 866836638668 in words is "eight hundred sixty-six billion, eight hundred thirty-six million, six hundred thirty-eight thousand, six hundred sixty-eight".