2112121221 has 8 divisors (see below), whose sum is σ = 3218470464. Its totient is φ = 1206926400.

The previous prime is 2112121213. The next prime is 2112121229. The reversal of 2112121221 is 1221212112.

It is an interprime number because it is at equal distance from previous prime (2112121213) and next prime (2112121229).

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

It is not a de Polignac number, because 2112121221 - 2³ = 2112121213 is a prime.

It is a super-2 number, since 2×2112121221² = 8922112104397061682, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2112121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2112121229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50288580 + ... + 50288621.

It is an arithmetic number, because the mean of its divisors is an integer number (402308808).

Almost surely, 2^2112121221 is an apocalyptic number.

2112121221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2112121221 is a deficient number, since it is larger than the sum of its proper divisors (1106349243).

2112121221 is a wasteful number, since it uses less digits than its factorization.

2112121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100577211.

The product of its digits is 32, while the sum is 15.

The square root of 2112121221 is about 45957.8200201010. The cubic root of 2112121221 is about 1283.0382782787.

Adding to 2112121221 its reverse (1221212112), we get a palindrome (3333333333).

The spelling of 2112121221 in words is "two billion, one hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".