21424530 has 16 divisors (see below), whose sum is σ = 51418944. Its totient is φ = 5713200.

The previous prime is 21424511. The next prime is 21424547. The reversal of 21424530 is 3542412.

It is a junction number, because it is equal to n+sod(n) for n = 21424497 and 21424506.

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, 357046 + ... + 357105.

It is an arithmetic number, because the mean of its divisors is an integer number (3213684).

Almost surely, 2^21424530 is an apocalyptic number.

21424530 is an abundant number, since it is smaller than the sum of its proper divisors (29994414).

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

21424530 is a wasteful number, since it uses less digits than its factorization.

21424530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714161.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21424530 is about 4628.6639541017. The cubic root of 21424530 is about 277.7391494137.

Adding to 21424530 its reverse (3542412), we get a palindrome (24966942).

The spelling of 21424530 in words is "twenty-one million, four hundred twenty-four thousand, five hundred thirty".