21421324 has 12 divisors (see below), whose sum is σ = 37962400. Its totient is φ = 10574928.

The previous prime is 21421319. The next prime is 21421333. The reversal of 21421324 is 42312412.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33579 + ... + 34210.

Almost surely, 2^21421324 is an apocalyptic number.

It is an amenable number.

21421324 is a deficient number, since it is larger than the sum of its proper divisors (16541076).

21421324 is a wasteful number, since it uses less digits than its factorization.

21421324 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67872 (or 67870 counting only the distinct ones).

The product of its digits is 384, while the sum is 19.

The square root of 21421324 is about 4628.3176209072. The cubic root of 21421324 is about 277.7252949498.

Adding to 21421324 its reverse (42312412), we get a palindrome (63733736).

The spelling of 21421324 in words is "twenty-one million, four hundred twenty-one thousand, three hundred twenty-four".