21354424 has 32 divisors (see below), whose sum is σ = 49281120. Its totient is φ = 8447616.

The previous prime is 21354413. The next prime is 21354433. The reversal of 21354424 is 42445312.

It is a happy number.

It is a super-2 number, since 2×21354424² = 912022848743552, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13939 + ... + 15394.

It is an arithmetic number, because the mean of its divisors is an integer number (1540035).

Almost surely, 2^21354424 is an apocalyptic number.

It is an amenable number.

21354424 is an abundant number, since it is smaller than the sum of its proper divisors (27926696).

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

21354424 is a wasteful number, since it uses less digits than its factorization.

21354424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29359 (or 29355 counting only the distinct ones).

The product of its digits is 3840, while the sum is 25.

The square root of 21354424 is about 4621.0847211450. The cubic root of 21354424 is about 277.4358762098.

Adding to 21354424 its reverse (42445312), we get a palindrome (63799736).

The spelling of 21354424 in words is "twenty-one million, three hundred fifty-four thousand, four hundred twenty-four".