121805920 has 48 divisors (see below), whose sum is σ = 289442160. Its totient is φ = 48438784.

The previous prime is 121805917. The next prime is 121805923. The reversal of 121805920 is 29508121.

It is an interprime number because it is at equal distance from previous prime (121805917) and next prime (121805923).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121805923) by changing a digit.

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, 26514 + ... + 30766.

It is an arithmetic number, because the mean of its divisors is an integer number (6030045).

Almost surely, 2^121805920 is an apocalyptic number.

121805920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121805920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144721080).

121805920 is an abundant number, since it is smaller than the sum of its proper divisors (167636240).

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

121805920 is a wasteful number, since it uses less digits than its factorization.

121805920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4447 (or 4439 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 121805920 is about 11036.5719315374. The cubic root of 121805920 is about 495.7044284794.

The spelling of 121805920 in words is "one hundred twenty-one million, eight hundred five thousand, nine hundred twenty".