21321322000 has 320 divisors, whose sum is σ = 60752540160. Its totient is φ = 7155456000.

The previous prime is 21321321997. The next prime is 21321322007. The reversal of 21321322000 is 22312312.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (21321322007) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 14673274 + ... + 14674726.

It is an arithmetic number, because the mean of its divisors is an integer number (189851688).

Almost surely, 2^21321322000 is an apocalyptic number.

21321322000 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 21321322000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30376270080).

21321322000 is an abundant number, since it is smaller than the sum of its proper divisors (39431218160).

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

21321322000 is a wasteful number, since it uses less digits than its factorization.

21321322000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1539 (or 1523 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21321322000 its reverse (22312312), we get a palindrome (21343634312).

The spelling of 21321322000 in words is "twenty-one billion, three hundred twenty-one million, three hundred twenty-two thousand".