212021021220 has 96 divisors (see below), whose sum is σ = 612927737856. Its totient is φ = 54725529600.

The previous prime is 212021021159. The next prime is 212021021239. The reversal of 212021021220 is 22120120212.

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 212021021220.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26901 + ... + 651740.

It is an arithmetic number, because the mean of its divisors is an integer number (6384663936).

Almost surely, 2^212021021220 is an apocalyptic number.

212021021220 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 212021021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306463868928).

212021021220 is an abundant number, since it is smaller than the sum of its proper divisors (400906716636).

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

212021021220 is a wasteful number, since it uses less digits than its factorization.

212021021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678821 (or 678819 counting only the distinct ones).

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

Adding to 212021021220 its reverse (22120120212), we get a palindrome (234141141432).

The spelling of 212021021220 in words is "two hundred twelve billion, twenty-one million, twenty-one thousand, two hundred twenty".