212120121 has 4 divisors (see below), whose sum is σ = 282826832. Its totient is φ = 141413412.

The previous prime is 212120107. The next prime is 212120137. The reversal of 212120121 is 121021212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 212120121 - 2¹¹ = 212118073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212120097 and 212120106.

It is not an unprimeable number, because it can be changed into a prime (212120141) 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 3 ways as a sum of consecutive naturals, for example, 35353351 + ... + 35353356.

It is an arithmetic number, because the mean of its divisors is an integer number (70706708).

Almost surely, 2^212120121 is an apocalyptic number.

It is an amenable number.

212120121 is a deficient number, since it is larger than the sum of its proper divisors (70706711).

212120121 is an equidigital number, since it uses as much as digits as its factorization.

212120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70706710.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 212120121 is about 14564.3441664910. The cubic root of 212120121 is about 596.3857923295.

Adding to 212120121 its reverse (121021212), we get a palindrome (333141333).

The spelling of 212120121 in words is "two hundred twelve million, one hundred twenty thousand, one hundred twenty-one".