21422424 has 64 divisors (see below), whose sum is σ = 57024000. Its totient is φ = 6687360.

The previous prime is 21422419. The next prime is 21422449. The reversal of 21422424 is 42422412.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21422424.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49489 + ... + 49919.

It is an arithmetic number, because the mean of its divisors is an integer number (891000).

Almost surely, 2^21422424 is an apocalyptic number.

21422424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21422424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28512000).

21422424 is an abundant number, since it is smaller than the sum of its proper divisors (35601576).

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

21422424 is a wasteful number, since it uses less digits than its factorization.

21422424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 568 (or 564 counting only the distinct ones).

The product of its digits is 1024, while the sum is 21.

The square root of 21422424 is about 4628.4364530584. The cubic root of 21422424 is about 277.7300486646.

Adding to 21422424 its reverse (42422412), we get a palindrome (63844836).

The spelling of 21422424 in words is "twenty-one million, four hundred twenty-two thousand, four hundred twenty-four".