212021221220 has 24 divisors (see below), whose sum is σ = 446649134904. Its totient is φ = 84540951296.

The previous prime is 212021221207. The next prime is 212021221283. The reversal of 212021221220 is 22122120212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12128176384 + 199893044836 = 110128^2 + 447094^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16714577 + ... + 16727256.

It is an arithmetic number, because the mean of its divisors is an integer number (18610380621).

Almost surely, 2^212021221220 is an apocalyptic number.

212021221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212021221220 is an abundant number, since it is smaller than the sum of its proper divisors (234627913684).

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

212021221220 is a wasteful number, since it uses less digits than its factorization.

212021221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33442159 (or 33442157 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 212021221220 its reverse (22122120212), we get a palindrome (234143341432).

The spelling of 212021221220 in words is "two hundred twelve billion, twenty-one million, two hundred twenty-one thousand, two hundred twenty".