12312121 has 4 divisors (see below), whose sum is σ = 12495952.
Its totient is φ = 12128292.
The previous prime is 12312119. The next prime is 12312143. The reversal of 12312121 is 12121321.
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 12312121 - 21 = 12312119 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (12312101) 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, 91815 + ... + 91948.
It is an arithmetic number, because the mean of its divisors is an integer number (3123988).
Almost surely, 212312121 is an apocalyptic number.
It is an amenable number.
12312121 is a deficient number, since it is larger than the sum of its proper divisors (183831).
12312121 is an equidigital number, since it uses as much as digits as its factorization.
12312121 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 183830.
The product of its digits is 24, while the sum is 13.
The square root of 12312121 is about 3508.8632062251.
The cubic root of 12312121 is about 230.9108243209.
Adding to 12312121 its reverse (12121321), we get a palindrome (24433442).
The spelling of 12312121 in words is "twelve million, three hundred twelve thousand, one hundred twenty-one".