121221904 has 20 divisors (see below), whose sum is σ = 242444800. Its totient is φ = 58655520.

The previous prime is 121221901. The next prime is 121221911. The reversal of 121221904 is 409122121.

121221904 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (121221901) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 121704 + ... + 122695.

It is an arithmetic number, because the mean of its divisors is an integer number (12122240).

Almost surely, 2^121221904 is an apocalyptic number.

It is an amenable number.

121221904 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

121221904 is a wasteful number, since it uses less digits than its factorization.

121221904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244438 (or 244432 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 121221904 is about 11010.0819252175. The cubic root of 121221904 is about 494.9109168670.

The spelling of 121221904 in words is "one hundred twenty-one million, two hundred twenty-one thousand, nine hundred four".