121999980 has 48 divisors (see below), whose sum is σ = 342687744. Its totient is φ = 32429760.

The previous prime is 121999967. The next prime is 121999991. The reversal of 121999980 is 89999121.

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, 16789 + ... + 22931.

It is an arithmetic number, because the mean of its divisors is an integer number (7139328).

Almost surely, 2^121999980 is an apocalyptic number.

121999980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121999980 is an abundant number, since it is smaller than the sum of its proper divisors (220687764).

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

121999980 is a wasteful number, since it uses less digits than its factorization.

121999980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6486 (or 6484 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 48.

The square root of 121999980 is about 11045.3601118298. The cubic root of 121999980 is about 495.9675392822.

The spelling of 121999980 in words is "one hundred twenty-one million, nine hundred ninety-nine thousand, nine hundred eighty".