21440230 has 64 divisors (see below), whose sum is σ = 47900160. Its totient is φ = 6741504.

The previous prime is 21440207. The next prime is 21440233. The reversal of 21440230 is 3204412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50961 + ... + 51379.

It is an arithmetic number, because the mean of its divisors is an integer number (748440).

Almost surely, 2^21440230 is an apocalyptic number.

21440230 is an abundant number, since it is smaller than the sum of its proper divisors (26459930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21440230 is a wasteful number, since it uses less digits than its factorization.

21440230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493.

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

The square root of 21440230 is about 4630.3595972667. The cubic root of 21440230 is about 277.8069757160.

Adding to 21440230 its reverse (3204412), we get a palindrome (24644642).

The spelling of 21440230 in words is "twenty-one million, four hundred forty thousand, two hundred thirty".