121721209199 has 8 divisors (see below), whose sum is σ = 123730486992. Its totient is φ = 119712378240.

The previous prime is 121721209157. The next prime is 121721209223. The reversal of 121721209199 is 991902127121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121721209199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121721209399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 461687 + ... + 675719.

It is an arithmetic number, because the mean of its divisors is an integer number (15466310874).

Almost surely, 2^121721209199 is an apocalyptic number.

121721209199 is a deficient number, since it is larger than the sum of its proper divisors (2009277793).

121721209199 is an equidigital number, since it uses as much as digits as its factorization.

121721209199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223417.

The product of its (nonzero) digits is 40824, while the sum is 44.

The spelling of 121721209199 in words is "one hundred twenty-one billion, seven hundred twenty-one million, two hundred nine thousand, one hundred ninety-nine".