12691728 has 100 divisors (see below), whose sum is σ = 42011200. Its totient is φ = 3623616.

The previous prime is 12691717. The next prime is 12691733. The reversal of 12691728 is 82719621.

It is a super-2 number, since 2×12691728² = 322159919251968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 12691692 and 12691701.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8373 + ... + 9771.

It is an arithmetic number, because the mean of its divisors is an integer number (420112).

Almost surely, 2^12691728 is an apocalyptic number.

12691728 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 12691728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21005600).

12691728 is an abundant number, since it is smaller than the sum of its proper divisors (29319472).

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

12691728 is a wasteful number, since it uses less digits than its factorization.

12691728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426 (or 1411 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 12691728 is about 3562.5451576085. The cubic root of 12691728 is about 233.2599896467.

The spelling of 12691728 in words is "twelve million, six hundred ninety-one thousand, seven hundred twenty-eight".