212121101112221 has 32 divisors (see below), whose sum is σ = 249284070927360. Its totient is φ = 176707109606400.

The previous prime is 212121101112209. The next prime is 212121101112223. The reversal of 212121101112221 is 122211101121212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 212121101112221 - 2²⁶ = 212121034003357 is a prime.

It is a super-3 number, since 3×212121101112221³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 212121101112193 and 212121101112202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121101112223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 645151415 + ... + 645480123.

It is an arithmetic number, because the mean of its divisors is an integer number (7790127216480).

Almost surely, 2^{212121101112221} is an apocalyptic number.

It is an amenable number.

212121101112221 is a deficient number, since it is larger than the sum of its proper divisors (37162969815139).

212121101112221 is a wasteful number, since it uses less digits than its factorization.

212121101112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337325.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 212121101112221 its reverse (122211101121212), we get a palindrome (334332202233433).

The spelling of 212121101112221 in words is "two hundred twelve trillion, one hundred twenty-one billion, one hundred one million, one hundred twelve thousand, two hundred twenty-one".