21322312 is nontrivially palindromic in base 10.
Almost surely, 221322312 is an apocalyptic number.
21322312 is a gapful number since it is divisible by the number (22) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 21322312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22032000).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21322312 is a wasteful number, since it uses less digits than its factorization.
21322312 is an evil number, because the sum of its binary digits is even.
The square root of 21322312 is about 4617.6089050503. The cubic root of 21322312 is about 277.2967404773.
The spelling of 21322312 in words is "twenty-one million, three hundred twenty-two thousand, three hundred twelve".