21222430424 has 32 divisors (see below), whose sum is σ = 42982519440. Its totient is φ = 9765360000.

The previous prime is 21222430423. The next prime is 21222430459. The reversal of 21222430424 is 42403422212.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a junction number, because it is equal to n+sod(n) for n = 21222430393 and 21222430402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222430423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273827 + ... + 342674.

Almost surely, 2^21222430424 is an apocalyptic number.

It is an amenable number.

21222430424 is an abundant number, since it is smaller than the sum of its proper divisors (21760089016).

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

21222430424 is a wasteful number, since it uses less digits than its factorization.

21222430424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616851 (or 616847 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21222430424 its reverse (42403422212), we get a palindrome (63625852636).

The spelling of 21222430424 in words is "twenty-one billion, two hundred twenty-two million, four hundred thirty thousand, four hundred twenty-four".