121557434564016 has 240 divisors, whose sum is σ = 371588378428800. Its totient is φ = 36788978304000.

The previous prime is 121557434563993. The next prime is 121557434564017. The reversal of 121557434564016 is 610465434755121.

121557434564016 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 5 + 74 + 3 + 4 + 564 + 0 + 1 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (121557434564017) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5006265796 + ... + 5006290076.

It is an arithmetic number, because the mean of its divisors is an integer number (1548284910120).

Almost surely, 2^{121557434564016} is an apocalyptic number.

121557434564016 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 121557434564016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185794189214400).

121557434564016 is an abundant number, since it is smaller than the sum of its proper divisors (250030943864784).

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

121557434564016 is a wasteful number, since it uses less digits than its factorization.

121557434564016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28176 (or 28167 counting only the distinct ones).

The product of its (nonzero) digits is 12096000, while the sum is 54.

The spelling of 121557434564016 in words is "one hundred twenty-one trillion, five hundred fifty-seven billion, four hundred thirty-four million, five hundred sixty-four thousand, sixteen".