121557829386240 has 1920 divisors, whose sum is σ = 478319458312080. Its totient is φ = 29516151914496.

The previous prime is 121557829386229. The next prime is 121557829386283. The reversal of 121557829386240 is 42683928755121.

It is a happy number.

121557829386240 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 5 + 7 + 8 + 2 + 9 + 386 + 240 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 186152877754 + ... + 186152878406.

It is a 1-persistent number, because it is pandigital, but 2⋅121557829386240 = 243115658772480 is not.

Almost surely, 2^{121557829386240} is an apocalyptic number.

121557829386240 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 121557829386240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239159729156040).

121557829386240 is an abundant number, since it is smaller than the sum of its proper divisors (356761628925840).

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

121557829386240 is an frugal number, since it uses more digits than its factorization.

121557829386240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809 (or 759 counting only the distinct ones).

The product of its (nonzero) digits is 58060800, while the sum is 63.

The spelling of 121557829386240 in words is "one hundred twenty-one trillion, five hundred fifty-seven billion, eight hundred twenty-nine million, three hundred eighty-six thousand, two hundred forty".