It is a congruent number.
Almost surely, 220221236 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 20221236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30226560).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
20221236 is a wasteful number, since it uses less digits than its factorization.
20221236 is an odious number, because the sum of its binary digits is odd.
The square root of 20221236 is about 4496.8028642581. The cubic root of 20221236 is about 272.4389718284.
Adding to 20221236 its reverse (63212202), we get a palindrome (83433438).
The spelling of 20221236 in words is "twenty million, two hundred twenty-one thousand, two hundred thirty-six".