121404209 has 2 divisors, whose sum is σ = 121404210. Its totient is φ = 121404208.

The previous prime is 121404181. The next prime is 121404211. The reversal of 121404209 is 902404121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121330225 + 73984 = 11015^2 + 272^2 .

It is an emirp because it is prime and its reverse (902404121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121404209 is a prime.

Together with 121404211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121404229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60702104 + 60702105.

It is an arithmetic number, because the mean of its divisors is an integer number (60702105).

Almost surely, 2^121404209 is an apocalyptic number.

It is an amenable number.

121404209 is a deficient number, since it is larger than the sum of its proper divisors (1).

121404209 is an equidigital number, since it uses as much as digits as its factorization.

121404209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 121404209 is about 11018.3578177512. The cubic root of 121404209 is about 495.1588905967.

The spelling of 121404209 in words is "one hundred twenty-one million, four hundred four thousand, two hundred nine".