21321321200000 has 384 divisors, whose sum is σ = 56290834656000. Its totient is φ = 8021134080000.

The previous prime is 21321321199963. The next prime is 21321321200017. The reversal of 21321321200000 is 212312312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1056389909 + ... + 1056410091.

It is an arithmetic number, because the mean of its divisors is an integer number (146590715250).

Almost surely, 2^{21321321200000} is an apocalyptic number.

21321321200000 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 21321321200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28145417328000).

21321321200000 is an abundant number, since it is smaller than the sum of its proper divisors (34969513456000).

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

21321321200000 is an equidigital number, since it uses as much as digits as its factorization.

21321321200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20380 (or 20348 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21321321200000 its reverse (212312312), we get a palindrome (21321533512312).

The spelling of 21321321200000 in words is "twenty-one trillion, three hundred twenty-one billion, three hundred twenty-one million, two hundred thousand".