121840009 has 2 divisors, whose sum is σ = 121840010. Its totient is φ = 121840008.

The previous prime is 121839983. The next prime is 121840063. The reversal of 121840009 is 900048121.

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., 111936400 + 9903609 = 10580^2 + 3147^2 .

It is a cyclic number.

It is not a de Polignac number, because 121840009 - 2⁷ = 121839881 is a prime.

It is not a weakly prime, because it can be changed into another prime (121840409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60920004 + 60920005.

It is an arithmetic number, because the mean of its divisors is an integer number (60920005).

Almost surely, 2^121840009 is an apocalyptic number.

It is an amenable number.

121840009 is a deficient number, since it is larger than the sum of its proper divisors (1).

121840009 is an equidigital number, since it uses as much as digits as its factorization.

121840009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 121840009 is about 11038.1161889156. The cubic root of 121840009 is about 495.7506673161.

The spelling of 121840009 in words is "one hundred twenty-one million, eight hundred forty thousand, nine".