21021224000 has 224 divisors, whose sum is σ = 61420369920. Its totient is φ = 6974208000.

The previous prime is 21021223981. The next prime is 21021224017. The reversal of 21021224000 is 42212012.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1729946 + ... + 1742054.

It is an arithmetic number, because the mean of its divisors is an integer number (274198080).

Almost surely, 2^21021224000 is an apocalyptic number.

21021224000 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 21021224000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30710184960).

21021224000 is an abundant number, since it is smaller than the sum of its proper divisors (40399145920).

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

21021224000 is a wasteful number, since it uses less digits than its factorization.

21021224000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12174 (or 12154 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21021224000 its reverse (42212012), we get a palindrome (21063436012).

The spelling of 21021224000 in words is "twenty-one billion, twenty-one million, two hundred twenty-four thousand".