12123432121 has 4 divisors (see below), whose sum is σ = 12124163044. Its totient is φ = 12122701200.

The previous prime is 12123432119. The next prime is 12123432133.

12123432121 is nontrivially palindromic in base 10.

12123432121 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6432842025 + 5690590096 = 80205^2 + 75436^2 .

It is a cyclic number.

It is not a de Polignac number, because 12123432121 - 2¹ = 12123432119 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12123432092 and 12123432101.

It is not an unprimeable number, because it can be changed into a prime (12123432821) 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, 339990 + ... + 373951.

It is an arithmetic number, because the mean of its divisors is an integer number (3031040761).

Almost surely, 2^12123432121 is an apocalyptic number.

It is an amenable number.

12123432121 is a deficient number, since it is larger than the sum of its proper divisors (730923).

12123432121 is an equidigital number, since it uses as much as digits as its factorization.

12123432121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 730922.

The product of its digits is 576, while the sum is 22.

The spelling of 12123432121 in words is "twelve billion, one hundred twenty-three million, four hundred thirty-two thousand, one hundred twenty-one".