121689917870400 has 2688 divisors, whose sum is σ = 511619774238720. Its totient is φ = 27872169984000.

The previous prime is 121689917870399. The next prime is 121689917870419. The reversal of 121689917870400 is 4078719986121.

121689917870400 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 8 + 9 + 91 + 78 + 70 + 400 = 666.

It is a super-2 number, since 2×121689917870400² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 89019690517 + ... + 89019691883.

It is an arithmetic number, because the mean of its divisors is an integer number (190334737440).

Almost surely, 2^{121689917870400} is an apocalyptic number.

121689917870400 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 121689917870400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255809887119360).

121689917870400 is an abundant number, since it is smaller than the sum of its proper divisors (389929856368320).

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

121689917870400 is a wasteful number, since it uses less digits than its factorization.

121689917870400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1590 (or 1569 counting only the distinct ones).

The product of its (nonzero) digits is 12192768, while the sum is 63.

The spelling of 121689917870400 in words is "one hundred twenty-one trillion, six hundred eighty-nine billion, nine hundred seventeen million, eight hundred seventy thousand, four hundred".