216820224 has 120 divisors (see below), whose sum is σ = 631542912. Its totient is φ = 71608320.

The previous prime is 216820223. The next prime is 216820237. The reversal of 216820224 is 422028612.

It is a happy number.

It is a super-2 number, since 2×216820224² = 94022019070820352, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216820223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 972177 + ... + 972399.

Almost surely, 2^216820224 is an apocalyptic number.

216820224 is a gapful number since it is divisible by the number (24) 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 216820224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315771456).

216820224 is an abundant number, since it is smaller than the sum of its proper divisors (414722688).

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

216820224 is a wasteful number, since it uses less digits than its factorization.

216820224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458 (or 439 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 216820224 is about 14724.8166032722. The cubic root of 216820224 is about 600.7585073735.

Adding to 216820224 its reverse (422028612), we get a palindrome (638848836).

The spelling of 216820224 in words is "two hundred sixteen million, eight hundred twenty thousand, two hundred twenty-four".