221121212 has 24 divisors (see below), whose sum is σ = 421419600. Its totient is φ = 100907136.

The previous prime is 221121209. The next prime is 221121217. The reversal of 221121212 is 212121122.

221121212 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121217) 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, 19262 + ... + 28517.

It is an arithmetic number, because the mean of its divisors is an integer number (17559150).

Almost surely, 2^221121212 is an apocalyptic number.

It is an amenable number.

221121212 is a deficient number, since it is larger than the sum of its proper divisors (200298388).

221121212 is a wasteful number, since it uses less digits than its factorization.

221121212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47885 (or 47883 counting only the distinct ones).

The product of its digits is 32, while the sum is 14.

The square root of 221121212 is about 14870.1449892057. The cubic root of 221121212 is about 604.7048734739.

Adding to 221121212 its reverse (212121122), we get a palindrome (433242334).

The spelling of 221121212 in words is "two hundred twenty-one million, one hundred twenty-one thousand, two hundred twelve".