121809218 has 8 divisors (see below), whose sum is σ = 183479040. Its totient is φ = 60649540.

The previous prime is 121809203. The next prime is 121809229. The reversal of 121809218 is 812908121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 126938 + ... + 127893.

It is an arithmetic number, because the mean of its divisors is an integer number (22934880).

Almost surely, 2^121809218 is an apocalyptic number.

121809218 is a deficient number, since it is larger than the sum of its proper divisors (61669822).

121809218 is a wasteful number, since it uses less digits than its factorization.

121809218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255072.

The product of its (nonzero) digits is 2304, while the sum is 32.

The square root of 121809218 is about 11036.7213428627. The cubic root of 121809218 is about 495.7089023136.

The spelling of 121809218 in words is "one hundred twenty-one million, eight hundred nine thousand, two hundred eighteen".