221111312 has 40 divisors (see below), whose sum is σ = 452649600. Its totient is φ = 104461952.

The previous prime is 221111309. The next prime is 221111329. The reversal of 221111312 is 213111122.

221111312 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221111312² = 97780424588722688, which contains 22 as substring.

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, 16739 + ... + 26877.

It is an arithmetic number, because the mean of its divisors is an integer number (11316240).

Almost surely, 2^221111312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221111312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (226324800).

221111312 is an abundant number, since it is smaller than the sum of its proper divisors (231538288).

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

221111312 is a wasteful number, since it uses less digits than its factorization.

221111312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10223 (or 10217 counting only the distinct ones).

The product of its digits is 24, while the sum is 14.

The square root of 221111312 is about 14869.8121037221. The cubic root of 221111312 is about 604.6958487591.

Adding to 221111312 its reverse (213111122), we get a palindrome (434222434).

The spelling of 221111312 in words is "two hundred twenty-one million, one hundred eleven thousand, three hundred twelve".