21424422 has 8 divisors (see below), whose sum is σ = 42848856. Its totient is φ = 7141472.

The previous prime is 21424421. The next prime is 21424439. The reversal of 21424422 is 22442412.

It is a sphenic number, since it is the product of 3 distinct primes.

21424422 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424421) 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, 1785363 + ... + 1785374.

It is an arithmetic number, because the mean of its divisors is an integer number (5356107).

Almost surely, 2^21424422 is an apocalyptic number.

21424422 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21424422 is a wasteful number, since it uses less digits than its factorization.

21424422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3570742.

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

The square root of 21424422 is about 4628.6522876535. The cubic root of 21424422 is about 277.7386827231.

Adding to 21424422 its reverse (22442412), we get a palindrome (43866834).

The spelling of 21424422 in words is "twenty-one million, four hundred twenty-four thousand, four hundred twenty-two".