12491728 has 10 divisors (see below), whose sum is σ = 24202754. Its totient is φ = 6245856.

The previous prime is 12491723. The next prime is 12491741. The reversal of 12491728 is 82719421.

It can be written as a sum of positive squares in only one way, i.e., 12446784 + 44944 = 3528^2 + 212^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12491693 and 12491702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12491723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390351 + ... + 390382.

Almost surely, 2^12491728 is an apocalyptic number.

It is an amenable number.

12491728 is a deficient number, since it is larger than the sum of its proper divisors (11711026).

12491728 is an equidigital number, since it uses as much as digits as its factorization.

12491728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780741 (or 780735 counting only the distinct ones).

The product of its digits is 8064, while the sum is 34.

The square root of 12491728 is about 3534.3638748720. The cubic root of 12491728 is about 232.0282367534.

The spelling of 12491728 in words is "twelve million, four hundred ninety-one thousand, seven hundred twenty-eight".