866915989520 has 160 divisors (see below), whose sum is σ = 2394940047360. Its totient is φ = 285570178560.

The previous prime is 866915989501. The next prime is 866915989549. The reversal of 866915989520 is 25989519668.

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, 2233409 + ... + 2592671.

It is an arithmetic number, because the mean of its divisors is an integer number (14968375296).

Almost surely, 2^866915989520 is an apocalyptic number.

866915989520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866915989520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1197470023680).

866915989520 is an abundant number, since it is smaller than the sum of its proper divisors (1528024057840).

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

866915989520 is a wasteful number, since it uses less digits than its factorization.

866915989520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359453 (or 359447 counting only the distinct ones).

The product of its (nonzero) digits is 83980800, while the sum is 68.

The spelling of 866915989520 in words is "eight hundred sixty-six billion, nine hundred fifteen million, nine hundred eighty-nine thousand, five hundred twenty".