212121320 has 64 divisors (see below), whose sum is σ = 508896000. Its totient is φ = 79342848.

The previous prime is 212121319. The next prime is 212121379. The reversal of 212121320 is 23121212.

It is a happy number.

212121320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 212121295 and 212121304.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58274 + ... + 61806.

It is an arithmetic number, because the mean of its divisors is an integer number (7951500).

Almost surely, 2^212121320 is an apocalyptic number.

212121320 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 212121320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (254448000).

212121320 is an abundant number, since it is smaller than the sum of its proper divisors (296774680).

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

212121320 is a wasteful number, since it uses less digits than its factorization.

212121320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3642 (or 3638 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 212121320 is about 14564.3853286021. The cubic root of 212121320 is about 596.3869160092.

Adding to 212121320 its reverse (23121212), we get a palindrome (235242532).

The spelling of 212121320 in words is "two hundred twelve million, one hundred twenty-one thousand, three hundred twenty".