12001021121 has 4 divisors (see below), whose sum is σ = 12522804672. Its totient is φ = 11479237572.

The previous prime is 12001021079. The next prime is 12001021127. The reversal of 12001021121 is 12112010021.

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 12001021121 - 2⁶ = 12001021057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12001021127) 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, 260891741 + ... + 260891786.

It is an arithmetic number, because the mean of its divisors is an integer number (3130701168).

Almost surely, 2^12001021121 is an apocalyptic number.

It is an amenable number.

12001021121 is a deficient number, since it is larger than the sum of its proper divisors (521783551).

12001021121 is an equidigital number, since it uses as much as digits as its factorization.

12001021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521783550.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 12001021121 its reverse (12112010021), we get a palindrome (24113031142).

The spelling of 12001021121 in words is "twelve billion, one million, twenty-one thousand, one hundred twenty-one".