21144320000 has 120 divisors (see below), whose sum is σ = 52834181400. Its totient is φ = 8457216000.

The previous prime is 21144319997. The next prime is 21144320011. The reversal of 21144320000 is 2344112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1271741 + ... + 1288259.

It is an arithmetic number, because the mean of its divisors is an integer number (440284845).

Almost surely, 2^21144320000 is an apocalyptic number.

21144320000 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 21144320000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26417090700).

21144320000 is an abundant number, since it is smaller than the sum of its proper divisors (31689861400).

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

21144320000 is an frugal number, since it uses more digits than its factorization.

21144320000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16561 (or 16526 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21144320000 its reverse (2344112), we get a palindrome (21146664112).

The spelling of 21144320000 in words is "twenty-one billion, one hundred forty-four million, three hundred twenty thousand".