2121223212 has 144 divisors (see below), whose sum is σ = 5933360160. Its totient is φ = 635959296.

The previous prime is 2121223207. The next prime is 2121223219. The reversal of 2121223212 is 2123221212.

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is not an unprimeable number, because it can be changed into a prime (2121223219) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1898478 + ... + 1899594.

It is an arithmetic number, because the mean of its divisors is an integer number (41203890).

Almost surely, 2^2121223212 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 2121223212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2966680080).

2121223212 is an abundant number, since it is smaller than the sum of its proper divisors (3812136948).

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

2121223212 is a wasteful number, since it uses less digits than its factorization.

2121223212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280 (or 1275 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 2121223212 is about 46056.7390508707. The cubic root of 2121223212 is about 1284.8786820419.

Adding to 2121223212 its reverse (2123221212), we get a palindrome (4244444424).

The spelling of 2121223212 in words is "two billion, one hundred twenty-one million, two hundred twenty-three thousand, two hundred twelve".