121212209 has 2 divisors, whose sum is σ = 121212210. Its totient is φ = 121212208.

The previous prime is 121212181. The next prime is 121212253. The reversal of 121212209 is 902212121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 114597025 + 6615184 = 10705^2 + 2572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121212209 is a prime.

It is a super-2 number, since 2×121212209² = 29384799221319362, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121212709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60606104 + 60606105.

It is an arithmetic number, because the mean of its divisors is an integer number (60606105).

Almost surely, 2^121212209 is an apocalyptic number.

It is an amenable number.

121212209 is a deficient number, since it is larger than the sum of its proper divisors (1).

121212209 is an equidigital number, since it uses as much as digits as its factorization.

121212209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 121212209 is about 11009.6416381279. The cubic root of 121212209 is about 494.8977226365.

The spelling of 121212209 in words is "one hundred twenty-one million, two hundred twelve thousand, two hundred nine".