21043430 has 8 divisors (see below), whose sum is σ = 37878192. Its totient is φ = 8417368.

The previous prime is 21043423. The next prime is 21043441. The reversal of 21043430 is 3434012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21043399 and 21043408.

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, 1052162 + ... + 1052181.

It is an arithmetic number, because the mean of its divisors is an integer number (4734774).

Almost surely, 2^21043430 is an apocalyptic number.

21043430 is a deficient number, since it is larger than the sum of its proper divisors (16834762).

21043430 is a wasteful number, since it uses less digits than its factorization.

21043430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2104350.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21043430 is about 4587.3118490026. The cubic root of 21043430 is about 276.0824772762.

Adding to 21043430 its reverse (3434012), we get a palindrome (24477442).

The spelling of 21043430 in words is "twenty-one million, forty-three thousand, four hundred thirty".