21223443384 has 768 divisors, whose sum is σ = 76422528000. Its totient is φ = 5218836480.

The previous prime is 21223443343. The next prime is 21223443427. The reversal of 21223443384 is 48334432212.

21223443384 is a `hidden beast` number, since 2 + 1 + 2 + 234 + 43 + 384 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 238465612 + ... + 238465700.

It is an arithmetic number, because the mean of its divisors is an integer number (99508500).

Almost surely, 2^21223443384 is an apocalyptic number.

21223443384 is a gapful number since it is divisible by the number (24) 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 21223443384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38211264000).

21223443384 is an abundant number, since it is smaller than the sum of its proper divisors (55199084616).

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

21223443384 is a wasteful number, since it uses less digits than its factorization.

21223443384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 213 counting only the distinct ones).

The product of its digits is 110592, while the sum is 36.

Adding to 21223443384 its reverse (48334432212), we get a palindrome (69557875596).

The spelling of 21223443384 in words is "twenty-one billion, two hundred twenty-three million, four hundred forty-three thousand, three hundred eighty-four".