121280561280 has 384 divisors, whose sum is σ = 449300779200. Its totient is φ = 31225098240.

The previous prime is 121280561243. The next prime is 121280561287. The reversal of 121280561280 is 82165082121.

121280561280 is a `hidden beast` number, since 1 + 2 + 12 + 8 + 0 + 561 + 2 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (121280561287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4496635 + ... + 4523525.

Almost surely, 2^121280561280 is an apocalyptic number.

121280561280 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 121280561280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224650389600).

121280561280 is an abundant number, since it is smaller than the sum of its proper divisors (328020217920).

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

121280561280 is an equidigital number, since it uses as much as digits as its factorization.

121280561280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26954 (or 26930 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The spelling of 121280561280 in words is "one hundred twenty-one billion, two hundred eighty million, five hundred sixty-one thousand, two hundred eighty".