21243124 has 24 divisors (see below), whose sum is σ = 42717248. Its totient is φ = 9054720.

The previous prime is 21243077. The next prime is 21243137. The reversal of 21243124 is 42134212.

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, 3439 + ... + 7369.

Almost surely, 2^21243124 is an apocalyptic number.

It is an amenable number.

21243124 is an abundant number, since it is smaller than the sum of its proper divisors (21474124).

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

21243124 is a wasteful number, since it uses less digits than its factorization.

21243124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4135 (or 4133 counting only the distinct ones).

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

The square root of 21243124 is about 4609.0263613913. The cubic root of 21243124 is about 276.9530345637.

Adding to 21243124 its reverse (42134212), we get a palindrome (63377336).

The spelling of 21243124 in words is "twenty-one million, two hundred forty-three thousand, one hundred twenty-four".