212121222120 has 192 divisors, whose sum is σ = 722008909440. Its totient is φ = 56005344000.

The previous prime is 212121222107. The next prime is 212121222143. The reversal of 212121222120 is 21222121212.

It is a happy number.

212121222120 is a `hidden beast` number, since 212 + 1 + 212 + 221 + 20 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 212121222093 and 212121222102.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 873685 + ... + 1089755.

It is an arithmetic number, because the mean of its divisors is an integer number (3760463070).

Almost surely, 2^212121222120 is an apocalyptic number.

212121222120 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 212121222120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361004454720).

212121222120 is an abundant number, since it is smaller than the sum of its proper divisors (509887687320).

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

212121222120 is a wasteful number, since it uses less digits than its factorization.

212121222120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216198 (or 216182 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 212121222120 its reverse (21222121212), we get a palindrome (233343343332).

The spelling of 212121222120 in words is "two hundred twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty".