12391128 has 48 divisors (see below), whose sum is σ = 33878520. Its totient is φ = 4091136.

The previous prime is 12391111. The next prime is 12391163. The reversal of 12391128 is 82119321.

12391128 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×12391128² = 307080106224768, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7375 + ... + 8897.

Almost surely, 2^12391128 is an apocalyptic number.

12391128 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12391128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16939260).

12391128 is an abundant number, since it is smaller than the sum of its proper divisors (21487392).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12391128 is a wasteful number, since it uses less digits than its factorization.

12391128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648 (or 1641 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 12391128 is about 3520.1034075720. The cubic root of 12391128 is about 231.4036905775.

The spelling of 12391128 in words is "twelve million, three hundred ninety-one thousand, one hundred twenty-eight".