2122121220 has 192 divisors, whose sum is σ = 6608770560. Its totient is φ = 507826176.

The previous prime is 2122121189. The next prime is 2122121227. The reversal of 2122121220 is 221212212.

2122121220 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 2122121220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2122121227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6779784 + ... + 6780096.

It is an arithmetic number, because the mean of its divisors is an integer number (34420680).

Almost surely, 2^2122121220 is an apocalyptic number.

2122121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2122121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3304385280).

2122121220 is an abundant number, since it is smaller than the sum of its proper divisors (4486649340).

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

2122121220 is a wasteful number, since it uses less digits than its factorization.

2122121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399 (or 363 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 2122121220 is about 46066.4869509278. The cubic root of 2122121220 is about 1285.0599718663.

Adding to 2122121220 its reverse (221212212), we get a palindrome (2343333432).

The spelling of 2122121220 in words is "two billion, one hundred twenty-two million, one hundred twenty-one thousand, two hundred twenty".