211221312 has 56 divisors (see below), whose sum is σ = 560076096. Its totient is φ = 70253568.

The previous prime is 211221301. The next prime is 211221313. The reversal of 211221312 is 213122112.

211221312 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×211221312² = 89228885286002688, 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 = 211221291 and 211221300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117573 + ... + 119355.

Almost surely, 2^211221312 is an apocalyptic number.

It is an amenable number.

211221312 is an abundant number, since it is smaller than the sum of its proper divisors (348854784).

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

211221312 is a wasteful number, since it uses less digits than its factorization.

211221312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2415 (or 2405 counting only the distinct ones).

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

The square root of 211221312 is about 14533.4549230388. The cubic root of 211221312 is about 595.5422517098.

Adding to 211221312 its reverse (213122112), we get a palindrome (424343424).

The spelling of 211221312 in words is "two hundred eleven million, two hundred twenty-one thousand, three hundred twelve".