121211817542400 has 1296 divisors, whose sum is σ = 448002499338240. Its totient is φ = 28818328780800.

The previous prime is 121211817542351. The next prime is 121211817542419. The reversal of 121211817542400 is 4245718112121.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 77352786417 + ... + 77352787983.

Almost surely, 2^{121211817542400} is an apocalyptic number.

121211817542400 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 121211817542400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224001249669120).

121211817542400 is an abundant number, since it is smaller than the sum of its proper divisors (326790681795840).

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

121211817542400 is a wasteful number, since it uses less digits than its factorization.

121211817542400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2422 (or 2390 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 39.

The spelling of 121211817542400 in words is "one hundred twenty-one trillion, two hundred eleven billion, eight hundred seventeen million, five hundred forty-two thousand, four hundred".