21001323321000 has 384 divisors, whose sum is σ = 79530528879360. Its totient is φ = 4953628224000.

The previous prime is 21001323320987. The next prime is 21001323321001. The reversal of 21001323321000 is 12332310012.

21001323321000 is a `hidden beast` number, since 2 + 100 + 132 + 332 + 100 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21001323321001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 796317 + ... + 6529683.

It is an arithmetic number, because the mean of its divisors is an integer number (207110752290).

Almost surely, 2^{21001323321000} is an apocalyptic number.

21001323321000 is a gapful number since it is divisible by the number (20) 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 21001323321000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39765264439680).

21001323321000 is an abundant number, since it is smaller than the sum of its proper divisors (58529205558360).

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

21001323321000 is a wasteful number, since it uses less digits than its factorization.

21001323321000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5733442 (or 5733425 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21001323321000 its reverse (12332310012), we get a palindrome (21013655631012).

The spelling of 21001323321000 in words is "twenty-one trillion, one billion, three hundred twenty-three million, three hundred twenty-one thousand".