212121321 has 8 divisors (see below), whose sum is σ = 284391744. Its totient is φ = 140632560.

The previous prime is 212121319. The next prime is 212121379. The reversal of 212121321 is 123121212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 212121321 - 2¹ = 212121319 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212121321.

It is not an unprimeable number, because it can be changed into a prime (212121421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194781 + ... + 195866.

It is an arithmetic number, because the mean of its divisors is an integer number (35548968).

Almost surely, 2^212121321 is an apocalyptic number.

It is an amenable number.

212121321 is a deficient number, since it is larger than the sum of its proper divisors (72270423).

212121321 is a wasteful number, since it uses less digits than its factorization.

212121321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390831.

The product of its digits is 48, while the sum is 15.

The square root of 212121321 is about 14564.3853629324. The cubic root of 212121321 is about 596.3869169463.

Adding to 212121321 its reverse (123121212), we get a palindrome (335242533).

The spelling of 212121321 in words is "two hundred twelve million, one hundred twenty-one thousand, three hundred twenty-one".