21233530 has 8 divisors (see below), whose sum is σ = 38220372. Its totient is φ = 8493408.

The previous prime is 21233503. The next prime is 21233579. The reversal of 21233530 is 3533212.

It can be written as a sum of positive squares in 2 ways, for example, as 17665209 + 3568321 = 4203^2 + 1889^2 .

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 = 21233498 and 21233507.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1061667 + ... + 1061686.

Almost surely, 2^21233530 is an apocalyptic number.

21233530 is a deficient number, since it is larger than the sum of its proper divisors (16986842).

21233530 is a wasteful number, since it uses less digits than its factorization.

21233530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2123360.

The product of its (nonzero) digits is 540, while the sum is 19.

The square root of 21233530 is about 4607.9854600465. The cubic root of 21233530 is about 276.9113349920.

Adding to 21233530 its reverse (3533212), we get a palindrome (24766742).

The spelling of 21233530 in words is "twenty-one million, two hundred thirty-three thousand, five hundred thirty".