21244336 has 20 divisors (see below), whose sum is σ = 41742864. Its totient is φ = 10472000.

The previous prime is 21244309. The next prime is 21244367. The reversal of 21244336 is 63344212.

It is a self number, because there is not a number n which added to its sum of digits gives 21244336.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8215 + ... + 10486.

Almost surely, 2^21244336 is an apocalyptic number.

It is an amenable number.

21244336 is a deficient number, since it is larger than the sum of its proper divisors (20498528).

21244336 is a wasteful number, since it uses less digits than its factorization.

21244336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18780 (or 18774 counting only the distinct ones).

The product of its digits is 3456, while the sum is 25.

The square root of 21244336 is about 4609.1578406472. The cubic root of 21244336 is about 276.9583015338.

Adding to 21244336 its reverse (63344212), we get a palindrome (84588548).

The spelling of 21244336 in words is "twenty-one million, two hundred forty-four thousand, three hundred thirty-six".