21224144000 has 128 divisors (see below), whose sum is σ = 52876212480. Its totient is φ = 8472345600.

The previous prime is 21224143999. The next prime is 21224144041. The reversal of 21224144000 is 44142212.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10286969 + ... + 10289031.

It is an arithmetic number, because the mean of its divisors is an integer number (413095410).

Almost surely, 2^21224144000 is an apocalyptic number.

21224144000 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 21224144000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26438106240).

21224144000 is an abundant number, since it is smaller than the sum of its proper divisors (31652068480).

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

21224144000 is an equidigital number, since it uses as much as digits as its factorization.

21224144000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2735 (or 2713 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21224144000 its reverse (44142212), we get a palindrome (21268286212).

The spelling of 21224144000 in words is "twenty-one billion, two hundred twenty-four million, one hundred forty-four thousand".