121705920 has 168 divisors, whose sum is σ = 478499424. Its totient is φ = 27813888.

The previous prime is 121705901. The next prime is 121705921. The reversal of 121705920 is 29507121.

121705920 is a `hidden beast` number, since 1 + 2 + 1 + 70 + 592 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121705921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17142 + ... + 23178.

Almost surely, 2^121705920 is an apocalyptic number.

121705920 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 121705920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239249712).

121705920 is an abundant number, since it is smaller than the sum of its proper divisors (356793504).

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

121705920 is a wasteful number, since it uses less digits than its factorization.

121705920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6067 (or 6054 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 121705920 is about 11032.0406090623. The cubic root of 121705920 is about 495.5687371697.

The spelling of 121705920 in words is "one hundred twenty-one million, seven hundred five thousand, nine hundred twenty".