21230224420 has 12 divisors (see below), whose sum is σ = 44583471324. Its totient is φ = 8492089760.

The previous prime is 21230224417. The next prime is 21230224429. The reversal of 21230224420 is 2442203212.

It can be written as a sum of positive squares in 2 ways, for example, as 3707348544 + 17522875876 = 60888^2 + 132374^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21230224391 and 21230224400.

It is not an unprimeable number, because it can be changed into a prime (21230224429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530755591 + ... + 530755630.

It is an arithmetic number, because the mean of its divisors is an integer number (3715289277).

Almost surely, 2^21230224420 is an apocalyptic number.

21230224420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21230224420 is an abundant number, since it is smaller than the sum of its proper divisors (23353246904).

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

21230224420 is a wasteful number, since it uses less digits than its factorization.

21230224420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061511230 (or 1061511228 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21230224420 its reverse (2442203212), we get a palindrome (23672427632).

The spelling of 21230224420 in words is "twenty-one billion, two hundred thirty million, two hundred twenty-four thousand, four hundred twenty".