121921920 has 192 divisors, whose sum is σ = 429146640. Its totient is φ = 31887360.

The previous prime is 121921913. The next prime is 121921957. The reversal of 121921920 is 29129121.

121921920 is a nontrivial binomial coefficient, being equal to C(15616, 2).

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 351187 + ... + 351533.

Almost surely, 2^121921920 is an apocalyptic number.

121921920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121921920 is the 15615-th triangular number and also the 7808-th hexagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121921920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (214573320).

121921920 is an abundant number, since it is smaller than the sum of its proper divisors (307224720).

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

121921920 is a wasteful number, since it uses less digits than its factorization.

121921920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 121921920 is about 11041.8259359582. The cubic root of 121921920 is about 495.8617373900.

The spelling of 121921920 in words is "one hundred twenty-one million, nine hundred twenty-one thousand, nine hundred twenty".