12547991121 has 32 divisors (see below), whose sum is σ = 17742721920. Its totient is φ = 7874496000.

The previous prime is 12547991089. The next prime is 12547991123. The reversal of 12547991121 is 12119974521.

It is not a de Polignac number, because 12547991121 - 2⁵ = 12547991089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12547991123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2245551 + ... + 2251131.

It is an arithmetic number, because the mean of its divisors is an integer number (554460060).

Almost surely, 2^12547991121 is an apocalyptic number.

It is an amenable number.

12547991121 is a deficient number, since it is larger than the sum of its proper divisors (5194730799).

12547991121 is a wasteful number, since it uses less digits than its factorization.

12547991121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6257.

The product of its digits is 45360, while the sum is 42.

The spelling of 12547991121 in words is "twelve billion, five hundred forty-seven million, nine hundred ninety-one thousand, one hundred twenty-one".