121210209 has 8 divisors (see below), whose sum is σ = 179570720. Its totient is φ = 80806788.

The previous prime is 121210183. The next prime is 121210213. The reversal of 121210209 is 902012121.

It is not a de Polignac number, because 121210209 - 2⁷ = 121210081 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121210191 and 121210200.

It is not an unprimeable number, because it can be changed into a prime (121212209) 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 7 ways as a sum of consecutive naturals, for example, 2244607 + ... + 2244660.

It is an arithmetic number, because the mean of its divisors is an integer number (22446340).

Almost surely, 2^121210209 is an apocalyptic number.

It is an amenable number.

121210209 is a deficient number, since it is larger than the sum of its proper divisors (58360511).

121210209 is an equidigital number, since it uses as much as digits as its factorization.

121210209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4489276 (or 4489270 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 121210209 is about 11009.5508082755. The cubic root of 121210209 is about 494.8950006860.

The spelling of 121210209 in words is "one hundred twenty-one million, two hundred ten thousand, two hundred nine".