Adding to 21304440442 its reverse (24404440312), we get a palindrome (45708880754).
It is a sphenic number, since it is the product of 3 distinct primes.
It is a self number, because there is not a number n which added to its sum of digits gives 21304440442.
It is an unprimeable number.
Almost surely, 221304440442 is an apocalyptic number.
21304440442 is a wasteful number, since it uses less digits than its factorization.
21304440442 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 174626624.
The spelling of 21304440442 in words is "twenty-one billion, three hundred four million, four hundred forty thousand, four hundred forty-two".