121720380 has 48 divisors (see below), whose sum is σ = 350034720. Its totient is φ = 31580928.

The previous prime is 121720369. The next prime is 121720399. The reversal of 121720380 is 83027121.

It is a self number, because there is not a number n which added to its sum of digits gives 121720380.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25195 + ... + 29634.

It is an arithmetic number, because the mean of its divisors is an integer number (7292390).

Almost surely, 2^121720380 is an apocalyptic number.

121720380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121720380 is an abundant number, since it is smaller than the sum of its proper divisors (228314340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121720380 is a wasteful number, since it uses less digits than its factorization.

121720380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54878 (or 54876 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 121720380 is about 11032.6959533924. The cubic root of 121720380 is about 495.5883627287.

The spelling of 121720380 in words is "one hundred twenty-one million, seven hundred twenty thousand, three hundred eighty".