12440243121 has 4 divisors (see below), whose sum is σ = 16586990832. Its totient is φ = 8293495412.

The previous prime is 12440243107. The next prime is 12440243131. The reversal of 12440243121 is 12134204421.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12134204421 = 3 ⋅4044734807.

It is a cyclic number.

It is not a de Polignac number, because 12440243121 - 2¹³ = 12440234929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12440243091 and 12440243100.

It is not an unprimeable number, because it can be changed into a prime (12440243131) 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, 2073373851 + ... + 2073373856.

It is an arithmetic number, because the mean of its divisors is an integer number (4146747708).

Almost surely, 2^12440243121 is an apocalyptic number.

It is an amenable number.

12440243121 is a deficient number, since it is larger than the sum of its proper divisors (4146747711).

12440243121 is an equidigital number, since it uses as much as digits as its factorization.

12440243121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4146747710.

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 12440243121 its reverse (12134204421), we get a palindrome (24574447542).

The spelling of 12440243121 in words is "twelve billion, four hundred forty million, two hundred forty-three thousand, one hundred twenty-one".