21255230 has 8 divisors (see below), whose sum is σ = 38259432. Its totient is φ = 8502088.

The previous prime is 21255217. The next prime is 21255239. The reversal of 21255230 is 3255212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255239) by changing a digit.

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, 1062752 + ... + 1062771.

It is an arithmetic number, because the mean of its divisors is an integer number (4782429).

Almost surely, 2^21255230 is an apocalyptic number.

21255230 is a deficient number, since it is larger than the sum of its proper divisors (17004202).

21255230 is a wasteful number, since it uses less digits than its factorization.

21255230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2125530.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 21255230 is about 4610.3394668940. The cubic root of 21255230 is about 277.0056344347.

The spelling of 21255230 in words is "twenty-one million, two hundred fifty-five thousand, two hundred thirty".