212243121 has 12 divisors (see below), whose sum is σ = 306879300. Its totient is φ = 141354240.

The previous prime is 212243107. The next prime is 212243153. The reversal of 212243121 is 121342212.

It is a happy number.

212243121 is a `hidden beast` number, since 212 + 2 + 431 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 94303521 + 117939600 = 9711^2 + 10860^2 .

It is not a de Polignac number, because 212243121 - 2⁷ = 212242993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212243094 and 212243103.

It is not an unprimeable number, because it can be changed into a prime (212243191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1800 + ... + 20681.

It is an arithmetic number, because the mean of its divisors is an integer number (25573275).

Almost surely, 2^212243121 is an apocalyptic number.

It is an amenable number.

212243121 is a deficient number, since it is larger than the sum of its proper divisors (94636179).

212243121 is a wasteful number, since it uses less digits than its factorization.

212243121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23536 (or 23533 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 212243121 is about 14568.5661957517. The cubic root of 212243121 is about 596.5010435026.

Adding to 212243121 its reverse (121342212), we get a palindrome (333585333).

Subtracting from 212243121 its reverse (121342212), we obtain a palindrome (90900909).

The spelling of 212243121 in words is "two hundred twelve million, two hundred forty-three thousand, one hundred twenty-one".