121660611430400 has 576 divisors, whose sum is σ = 356984370288000. Its totient is φ = 40233192652800.

The previous prime is 121660611430357. The next prime is 121660611430439. The reversal of 121660611430400 is 4034116066121.

It is a super-4 number, since 4×121660611430400⁴ (a number of 57 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (35).

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 47 ways as a sum of consecutive naturals, for example, 11339412236 + ... + 11339422964.

It is an arithmetic number, because the mean of its divisors is an integer number (619764531750).

Almost surely, 2^{121660611430400} is an apocalyptic number.

121660611430400 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 121660611430400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178492185144000).

121660611430400 is an abundant number, since it is smaller than the sum of its proper divisors (235323758857600).

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

121660611430400 is a wasteful number, since it uses less digits than its factorization.

121660611430400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11888 (or 11863 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

Adding to 121660611430400 its reverse (4034116066121), we get a palindrome (125694727496521).

The spelling of 121660611430400 in words is "one hundred twenty-one trillion, six hundred sixty billion, six hundred eleven million, four hundred thirty thousand, four hundred".