212121020220 has 96 divisors (see below), whose sum is σ = 610371236160. Its totient is φ = 55009443840.

The previous prime is 212121020201. The next prime is 212121020227. The reversal of 212121020220 is 22020121212.

It is a super-3 number, since 3×212121020220³ (a number of 35 digits) contains 333 as substring.

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 212121020220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121020227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 632236 + ... + 907724.

It is an arithmetic number, because the mean of its divisors is an integer number (6358033710).

Almost surely, 2^212121020220 is an apocalyptic number.

212121020220 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 212121020220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305185618080).

212121020220 is an abundant number, since it is smaller than the sum of its proper divisors (398250215940).

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

212121020220 is a wasteful number, since it uses less digits than its factorization.

212121020220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275855 (or 275853 counting only the distinct ones).

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

Adding to 212121020220 its reverse (22020121212), we get a palindrome (234141141432).

The spelling of 212121020220 in words is "two hundred twelve billion, one hundred twenty-one million, twenty thousand, two hundred twenty".