21260244 has 12 divisors (see below), whose sum is σ = 49607264. Its totient is φ = 7086744.

The previous prime is 21260233. The next prime is 21260273. The reversal of 21260244 is 44206212.

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

It is a zygodrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 21260244.

It is a congruent number.

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, 885832 + ... + 885855.

Almost surely, 2^21260244 is an apocalyptic number.

It is an amenable number.

21260244 is an abundant number, since it is smaller than the sum of its proper divisors (28347020).

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

21260244 is a wasteful number, since it uses less digits than its factorization.

21260244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1771694 (or 1771692 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 21260244 is about 4610.8832125744. The cubic root of 21260244 is about 277.0274141261.

Adding to 21260244 its reverse (44206212), we get a palindrome (65466456).

The spelling of 21260244 in words is "twenty-one million, two hundred sixty thousand, two hundred forty-four".