21242244 has 12 divisors (see below), whose sum is σ = 49565264. Its totient is φ = 7080744.

The previous prime is 21242237. The next prime is 21242339. The reversal of 21242244 is 44224212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-4 number, since 4×21242244⁴ (a number of 30 digits) contains 4444 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21242244.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 885082 + ... + 885105.

Almost surely, 2^21242244 is an apocalyptic number.

It is an amenable number.

21242244 is an abundant number, since it is smaller than the sum of its proper divisors (28323020).

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

21242244 is a wasteful number, since it uses less digits than its factorization.

21242244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1770194 (or 1770192 counting only the distinct ones).

The product of its digits is 1024, while the sum is 21.

The square root of 21242244 is about 4608.9308955548. The cubic root of 21242244 is about 276.9492102355.

Adding to 21242244 its reverse (44224212), we get a palindrome (65466456).

The spelling of 21242244 in words is "twenty-one million, two hundred forty-two thousand, two hundred forty-four".