866521630000 has 400 divisors, whose sum is σ = 2306243016000. Its totient is φ = 313367040000.

The previous prime is 866521629997. The next prime is 866521630027. The reversal of 866521630000 is 36125668.

It is a tau number, because it is divible by the number of its divisors (400).

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 79 ways as a sum of consecutive naturals, for example, 2482869826 + ... + 2482870174.

It is an arithmetic number, because the mean of its divisors is an integer number (5765607540).

Almost surely, 2^866521630000 is an apocalyptic number.

866521630000 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 866521630000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1153121508000).

866521630000 is an abundant number, since it is smaller than the sum of its proper divisors (1439721386000).

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

866521630000 is a wasteful number, since it uses less digits than its factorization.

866521630000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730 (or 709 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 866521630000 its reverse (36125668), we get a palindrome (866557755668).

The spelling of 866521630000 in words is "eight hundred sixty-six billion, five hundred twenty-one million, six hundred thirty thousand".