21244012 has 12 divisors (see below), whose sum is σ = 37807560. Its totient is φ = 10441856.

The previous prime is 21244001. The next prime is 21244061. The reversal of 21244012 is 21044212.

It is a super-2 number, since 2×21244012² = 902616091712288, which contains 22 as substring.

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, 44773 + ... + 45244.

It is an arithmetic number, because the mean of its divisors is an integer number (3150630).

Almost surely, 2^21244012 is an apocalyptic number.

It is an amenable number.

21244012 is a deficient number, since it is larger than the sum of its proper divisors (16563548).

21244012 is a wasteful number, since it uses less digits than its factorization.

21244012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90080 (or 90078 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21244012 is about 4609.1226930946. The cubic root of 21244012 is about 276.9568935515.

Adding to 21244012 its reverse (21044212), we get a palindrome (42288224).

The spelling of 21244012 in words is "twenty-one million, two hundred forty-four thousand, twelve".