121540642560 has 360 divisors, whose sum is σ = 449902141920. Its totient is φ = 31292448768.

The previous prime is 121540642523. The next prime is 121540642577. The reversal of 121540642560 is 65246045121.

121540642560 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 4 + 0 + 642 + 5 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

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

It is a congruent number.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 2986509 + ... + 3026931.

It is an arithmetic number, because the mean of its divisors is an integer number (1249728172).

Almost surely, 2^121540642560 is an apocalyptic number.

121540642560 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 121540642560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224951070960).

121540642560 is an abundant number, since it is smaller than the sum of its proper divisors (328361499360).

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

121540642560 is an equidigital number, since it uses as much as digits as its factorization.

121540642560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40485 (or 40462 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

Adding to 121540642560 its reverse (65246045121), we get a palindrome (186786687681).

The spelling of 121540642560 in words is "one hundred twenty-one billion, five hundred forty million, six hundred forty-two thousand, five hundred sixty".