21030424 has 16 divisors (see below), whose sum is σ = 39973320. Its totient is φ = 10370880.

The previous prime is 21030403. The next prime is 21030463. The reversal of 21030424 is 42403012.

It is a junction number, because it is equal to n+sod(n) for n = 21030398 and 21030407.

It is a congruent number.

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, 17422 + ... + 18589.

Almost surely, 2^21030424 is an apocalyptic number.

It is an amenable number.

21030424 is a deficient number, since it is larger than the sum of its proper divisors (18942896).

21030424 is a wasteful number, since it uses less digits than its factorization.

21030424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36090 (or 36086 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21030424 is about 4585.8940240699. The cubic root of 21030424 is about 276.0255874898.

Adding to 21030424 its reverse (42403012), we get a palindrome (63433436).

The spelling of 21030424 in words is "twenty-one million, thirty thousand, four hundred twenty-four".