121289209 has 2 divisors, whose sum is σ = 121289210. Its totient is φ = 121289208.

The previous prime is 121289177. The next prime is 121289221. The reversal of 121289209 is 902982121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75429225 + 45859984 = 8685^2 + 6772^2 .

It is a cyclic number.

It is not a de Polignac number, because 121289209 - 2⁵ = 121289177 is a prime.

It is a super-2 number, since 2×121289209² = 29422144439691362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (121289239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60644604 + 60644605.

It is an arithmetic number, because the mean of its divisors is an integer number (60644605).

Almost surely, 2^121289209 is an apocalyptic number.

It is an amenable number.

121289209 is a deficient number, since it is larger than the sum of its proper divisors (1).

121289209 is an equidigital number, since it uses as much as digits as its factorization.

121289209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 121289209 is about 11013.1380178403. The cubic root of 121289209 is about 495.0024949709.

The spelling of 121289209 in words is "one hundred twenty-one million, two hundred eighty-nine thousand, two hundred nine".