121516555776 has 960 divisors, whose sum is σ = 441379749888. Its totient is φ = 28993536000.

The previous prime is 121516555739. The next prime is 121516555777. The reversal of 121516555776 is 677555615121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121516555777) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 927607231 + ... + 927607361.

Almost surely, 2^121516555776 is an apocalyptic number.

121516555776 is a gapful number since it is divisible by the number (16) 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 121516555776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220689874944).

121516555776 is an abundant number, since it is smaller than the sum of its proper divisors (319863194112).

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

121516555776 is a wasteful number, since it uses less digits than its factorization.

121516555776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235 (or 208 counting only the distinct ones).

The product of its digits is 2205000, while the sum is 51.

The spelling of 121516555776 in words is "one hundred twenty-one billion, five hundred sixteen million, five hundred fifty-five thousand, seven hundred seventy-six".