121981220 has 24 divisors (see below), whose sum is σ = 256377408. Its totient is φ = 48751200.

The previous prime is 121981169. The next prime is 121981247. The reversal of 121981220 is 22189121.

It is a self number, because there is not a number n which added to its sum of digits gives 121981220.

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 7 ways as a sum of consecutive naturals, for example, 34955 + ... + 38285.

It is an arithmetic number, because the mean of its divisors is an integer number (10682392).

Almost surely, 2^121981220 is an apocalyptic number.

121981220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121981220 is an abundant number, since it is smaller than the sum of its proper divisors (134396188).

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

121981220 is a wasteful number, since it uses less digits than its factorization.

121981220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5171 (or 5169 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 121981220 is about 11044.5108538133. The cubic root of 121981220 is about 495.9421162507.

The spelling of 121981220 in words is "one hundred twenty-one million, nine hundred eighty-one thousand, two hundred twenty".