12017127721 has 4 divisors (see below), whose sum is σ = 12017361744. Its totient is φ = 12016893700.

The previous prime is 12017127713. The next prime is 12017127781. The reversal of 12017127721 is 12772171021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12017127721 - 2³ = 12017127713 is a prime.

It is a super-2 number, since 2×12017127721² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12017127781) 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, 2875 + ... + 155056.

It is an arithmetic number, because the mean of its divisors is an integer number (3004340436).

Almost surely, 2^12017127721 is an apocalyptic number.

It is an amenable number.

12017127721 is a deficient number, since it is larger than the sum of its proper divisors (234023).

12017127721 is an equidigital number, since it uses as much as digits as its factorization.

12017127721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234022.

The product of its (nonzero) digits is 2744, while the sum is 31.

Adding to 12017127721 its reverse (12772171021), we get a palindrome (24789298742).

The spelling of 12017127721 in words is "twelve billion, seventeen million, one hundred twenty-seven thousand, seven hundred twenty-one".