21243230 has 8 divisors (see below), whose sum is σ = 38237832. Its totient is φ = 8497288.

The previous prime is 21243227. The next prime is 21243253. The reversal of 21243230 is 3234212.

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 = 21243199 and 21243208.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1062152 + ... + 1062171.

It is an arithmetic number, because the mean of its divisors is an integer number (4779729).

Almost surely, 2^21243230 is an apocalyptic number.

21243230 is a deficient number, since it is larger than the sum of its proper divisors (16994602).

21243230 is a wasteful number, since it uses less digits than its factorization.

21243230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2124330.

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

The square root of 21243230 is about 4609.0378605518. The cubic root of 21243230 is about 276.9534952143.

Adding to 21243230 its reverse (3234212), we get a palindrome (24477442).

The spelling of 21243230 in words is "twenty-one million, two hundred forty-three thousand, two hundred thirty".