121655788320 has 192 divisors, whose sum is σ = 419394858624. Its totient is φ = 29397688320.

The previous prime is 121655788291. The next prime is 121655788343. The reversal of 121655788320 is 23887556121.

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

It is a self number, because there is not a number n which added to its sum of digits gives 121655788320.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1615834 + ... + 1689446.

It is an arithmetic number, because the mean of its divisors is an integer number (2184348222).

Almost surely, 2^121655788320 is an apocalyptic number.

121655788320 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 121655788320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (209697429312).

121655788320 is an abundant number, since it is smaller than the sum of its proper divisors (297739070304).

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

121655788320 is a wasteful number, since it uses less digits than its factorization.

121655788320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73955 (or 73947 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 48.

The spelling of 121655788320 in words is "one hundred twenty-one billion, six hundred fifty-five million, seven hundred eighty-eight thousand, three hundred twenty".