121861781760 has 144 divisors (see below), whose sum is σ = 389335887360. Its totient is φ = 32484802560.

The previous prime is 121861781737. The next prime is 121861781773. The reversal of 121861781760 is 67187168121.

It is a Harshad number since it is a multiple of its sum of digits (48).

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 15 ways as a sum of consecutive naturals, for example, 18547756 + ... + 18554324.

It is an arithmetic number, because the mean of its divisors is an integer number (2703721440).

Almost surely, 2^121861781760 is an apocalyptic number.

121861781760 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 121861781760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194667943680).

121861781760 is an abundant number, since it is smaller than the sum of its proper divisors (267474105600).

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

121861781760 is an equidigital number, since it uses as much as digits as its factorization.

121861781760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11424 (or 11410 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 48.

The spelling of 121861781760 in words is "one hundred twenty-one billion, eight hundred sixty-one million, seven hundred eighty-one thousand, seven hundred sixty".