121556720 has 40 divisors (see below), whose sum is σ = 284285376. Its totient is φ = 48336128.

The previous prime is 121556717. The next prime is 121556731. The reversal of 121556720 is 27655121.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9449 + ... + 18231.

Almost surely, 2^121556720 is an apocalyptic number.

121556720 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 121556720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142142688).

121556720 is an abundant number, since it is smaller than the sum of its proper divisors (162728656).

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

121556720 is a wasteful number, since it uses less digits than its factorization.

121556720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8969 (or 8963 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 121556720 is about 11025.2764137685. The cubic root of 121556720 is about 495.3661474896.

The spelling of 121556720 in words is "one hundred twenty-one million, five hundred fifty-six thousand, seven hundred twenty".