121806519988608 has 1536 divisors, whose sum is σ = 449662304931840. Its totient is φ = 30798346715136.

The previous prime is 121806519988591. The next prime is 121806519988619. The reversal of 121806519988608 is 806889915608121.

121806519988608 is a `hidden beast` number, since 1 + 2 + 1 + 8 + 0 + 6 + 5 + 1 + 9 + 9 + 8 + 8 + 608 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 65032844760 + ... + 65032846632.

It is an arithmetic number, because the mean of its divisors is an integer number (292748896440).

Almost surely, 2^{121806519988608} is an apocalyptic number.

121806519988608 is a gapful number since it is divisible by the number (18) 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 121806519988608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224831152465920).

121806519988608 is an abundant number, since it is smaller than the sum of its proper divisors (327855784943232).

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

121806519988608 is a wasteful number, since it uses less digits than its factorization.

121806519988608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2224 (or 2209 counting only the distinct ones).

The product of its (nonzero) digits is 119439360, while the sum is 72.

The spelling of 121806519988608 in words is "one hundred twenty-one trillion, eight hundred six billion, five hundred nineteen million, nine hundred eighty-eight thousand, six hundred eight".