12128331 has 4 divisors (see below), whose sum is σ = 16171112. Its totient is φ = 8085552.

The previous prime is 12128329. The next prime is 12128339. The reversal of 12128331 is 13382121.

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

It is not a de Polignac number, because 12128331 - 2¹ = 12128329 is a prime.

It is a super-2 number, since 2×12128331² = 294192825691122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12128298 and 12128307.

It is not an unprimeable number, because it can be changed into a prime (12128339) 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, 2021386 + ... + 2021391.

It is an arithmetic number, because the mean of its divisors is an integer number (4042778).

Almost surely, 2^12128331 is an apocalyptic number.

12128331 is a deficient number, since it is larger than the sum of its proper divisors (4042781).

12128331 is an equidigital number, since it uses as much as digits as its factorization.

12128331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4042780.

The product of its digits is 288, while the sum is 21.

The square root of 12128331 is about 3482.5753401757. The cubic root of 12128331 is about 229.7560804143.

The spelling of 12128331 in words is "twelve million, one hundred twenty-eight thousand, three hundred thirty-one".