121121809728 has 56 divisors (see below), whose sum is σ = 320584933632. Its totient is φ = 40359220224.

The previous prime is 121121809717. The next prime is 121121809733. The reversal of 121121809728 is 827908121121.

It is a self number, because there is not a number n which added to its sum of digits gives 121121809728.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 419601 + ... + 646767.

Almost surely, 2^121121809728 is an apocalyptic number.

It is an amenable number.

121121809728 is an abundant number, since it is smaller than the sum of its proper divisors (199463123904).

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

121121809728 is a wasteful number, since it uses less digits than its factorization.

121121809728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229959 (or 229949 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 42.

The spelling of 121121809728 in words is "one hundred twenty-one billion, one hundred twenty-one million, eight hundred nine thousand, seven hundred twenty-eight".