21243244 has 18 divisors (see below), whose sum is σ = 40863452. Its totient is φ = 9655800.

The previous prime is 21243227. The next prime is 21243253. The reversal of 21243244 is 44234212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21462 + ... + 22429.

Almost surely, 2^21243244 is an apocalyptic number.

It is an amenable number.

21243244 is a deficient number, since it is larger than the sum of its proper divisors (19620208).

21243244 is a wasteful number, since it uses less digits than its factorization.

21243244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43917 (or 43904 counting only the distinct ones).

The product of its digits is 1536, while the sum is 22.

The square root of 21243244 is about 4609.0393793067. The cubic root of 21243244 is about 276.9535560549.

Adding to 21243244 its reverse (44234212), we get a palindrome (65477456).

The spelling of 21243244 in words is "twenty-one million, two hundred forty-three thousand, two hundred forty-four".