221316816 has 40 divisors (see below), whose sum is σ = 653412544. Its totient is φ = 63233280.

The previous prime is 221316803. The next prime is 221316827. The reversal of 221316816 is 618613122.

It is a super-2 number, since 2×221316816² = 97962266088755712, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 329005 + ... + 329676.

Almost surely, 2^221316816 is an apocalyptic number.

It is an amenable number.

221316816 is an abundant number, since it is smaller than the sum of its proper divisors (432095728).

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

221316816 is a wasteful number, since it uses less digits than its factorization.

221316816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658699 (or 658693 counting only the distinct ones).

The product of its digits is 3456, while the sum is 30.

The square root of 221316816 is about 14876.7206063702. The cubic root of 221316816 is about 604.8831283934.

Adding to 221316816 its reverse (618613122), we get a palindrome (839929938).

The spelling of 221316816 in words is "two hundred twenty-one million, three hundred sixteen thousand, eight hundred sixteen".