12181787621867 has 4 divisors (see below), whose sum is σ = 12183863243280. Its totient is φ = 12179712000456.

The previous prime is 12181787621849. The next prime is 12181787621873. The reversal of 12181787621867 is 76812678718121.

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

It is a cyclic number.

It is not a de Polignac number, because 12181787621867 - 2⁸ = 12181787621611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12181787621167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1037801903 + ... + 1037813640.

It is an arithmetic number, because the mean of its divisors is an integer number (3045965810820).

Almost surely, 2^{12181787621867} is an apocalyptic number.

12181787621867 is a deficient number, since it is larger than the sum of its proper divisors (2075621413).

12181787621867 is an equidigital number, since it uses as much as digits as its factorization.

12181787621867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2075621412.

The product of its digits is 25288704, while the sum is 65.

The spelling of 12181787621867 in words is "twelve trillion, one hundred eighty-one billion, seven hundred eighty-seven million, six hundred twenty-one thousand, eight hundred sixty-seven".