21244230 has 48 divisors (see below), whose sum is σ = 63127584. Its totient is φ = 4855680.

The previous prime is 21244229. The next prime is 21244231. The reversal of 21244230 is 3244212.

It is an interprime number because it is at equal distance from previous prime (21244229) and next prime (21244231).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244231) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16231 + ... + 17490.

It is an arithmetic number, because the mean of its divisors is an integer number (1315158).

Almost surely, 2^21244230 is an apocalyptic number.

21244230 is an abundant number, since it is smaller than the sum of its proper divisors (41883354).

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

21244230 is a wasteful number, since it uses less digits than its factorization.

21244230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33741 (or 33738 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 21244230 is about 4609.1463417861. The cubic root of 21244230 is about 276.9578408992.

Subtracting from 21244230 its sum of digits (18), we obtain a palindrome (21244212).

Adding to 21244230 its reverse (3244212), we get a palindrome (24488442).

The spelling of 21244230 in words is "twenty-one million, two hundred forty-four thousand, two hundred thirty".