21044222430 has 128 divisors (see below), whose sum is σ = 63193153536. Its totient is φ = 4357238400.

The previous prime is 21044222401. The next prime is 21044222443. The reversal of 21044222430 is 3422244012.

It is a self number, because there is not a number n which added to its sum of digits gives 21044222430.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 637635 + ... + 669825.

It is an arithmetic number, because the mean of its divisors is an integer number (493696512).

Almost surely, 2^21044222430 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21044222430, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31596576768).

21044222430 is an abundant number, since it is smaller than the sum of its proper divisors (42148931106).

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

21044222430 is a wasteful number, since it uses less digits than its factorization.

21044222430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32502.

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21044222430 its reverse (3422244012), we get a palindrome (24466466442).

The spelling of 21044222430 in words is "twenty-one billion, forty-four million, two hundred twenty-two thousand, four hundred thirty".