121121210209 has 4 divisors (see below), whose sum is σ = 123406516116. Its totient is φ = 118835904304.

The previous prime is 121121210201. The next prime is 121121210237. The reversal of 121121210209 is 902012121121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42551438400 + 78569771809 = 206280^2 + 280303^2 .

It is a cyclic number.

It is not a de Polignac number, because 121121210209 - 2³ = 121121210201 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121121210209.

It is not an unprimeable number, because it can be changed into a prime (121121210201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1142652874 + ... + 1142652979.

It is an arithmetic number, because the mean of its divisors is an integer number (30851629029).

Almost surely, 2^121121210209 is an apocalyptic number.

It is an amenable number.

121121210209 is a deficient number, since it is larger than the sum of its proper divisors (2285305907).

121121210209 is an equidigital number, since it uses as much as digits as its factorization.

121121210209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2285305906.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 121121210209 in words is "one hundred twenty-one billion, one hundred twenty-one million, two hundred ten thousand, two hundred nine".