121557107473 has 4 divisors (see below), whose sum is σ = 124842434740. Its totient is φ = 118271780208.

The previous prime is 121557107453. The next prime is 121557107491. The reversal of 121557107473 is 374701755121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 77822587089 + 43734520384 = 278967^2 + 209128^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121557107473 is a prime.

It is a super-2 number, since 2×121557107473² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121557107453) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1642663578 + ... + 1642663651.

It is an arithmetic number, because the mean of its divisors is an integer number (31210608685).

Almost surely, 2^121557107473 is an apocalyptic number.

It is an amenable number.

121557107473 is a deficient number, since it is larger than the sum of its proper divisors (3285327267).

121557107473 is an equidigital number, since it uses as much as digits as its factorization.

121557107473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3285327266.

The product of its (nonzero) digits is 205800, while the sum is 43.

The spelling of 121557107473 in words is "one hundred twenty-one billion, five hundred fifty-seven million, one hundred seven thousand, four hundred seventy-three".