21124422424 has 64 divisors (see below), whose sum is σ = 46388427840. Its totient is φ = 8830947840.

The previous prime is 21124422421. The next prime is 21124422437. The reversal of 21124422424 is 42422442112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (28).

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

It is a junction number, because it is equal to n+sod(n) for n = 21124422392 and 21124422401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124422421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 492894 + ... + 534034.

It is an arithmetic number, because the mean of its divisors is an integer number (724819185).

Almost surely, 2^21124422424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21124422424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23194213920).

21124422424 is an abundant number, since it is smaller than the sum of its proper divisors (25264005416).

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

21124422424 is a wasteful number, since it uses less digits than its factorization.

21124422424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41380 (or 41376 counting only the distinct ones).

The product of its digits is 8192, while the sum is 28.

Adding to 21124422424 its reverse (42422442112), we get a palindrome (63546864536).

The spelling of 21124422424 in words is "twenty-one billion, one hundred twenty-four million, four hundred twenty-two thousand, four hundred twenty-four".