221211312 has 40 divisors (see below), whose sum is σ = 653101056. Its totient is φ = 63203136.

The previous prime is 221211269. The next prime is 221211379. The reversal of 221211312 is 213112122.

It is a super-2 number, since 2×221211312² = 97868889113522688, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 221211291 and 221211300.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 328848 + ... + 329519.

Almost surely, 2^221211312 is an apocalyptic number.

It is an amenable number.

221211312 is an abundant number, since it is smaller than the sum of its proper divisors (431889744).

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

221211312 is a wasteful number, since it uses less digits than its factorization.

221211312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658385 (or 658379 counting only the distinct ones).

The product of its digits is 48, while the sum is 15.

The square root of 221211312 is about 14873.1742408942. The cubic root of 221211312 is about 604.7869951152.

Adding to 221211312 its reverse (213112122), we get a palindrome (434323434).

The spelling of 221211312 in words is "two hundred twenty-one million, two hundred eleven thousand, three hundred twelve".