12697728 has 64 divisors (see below), whose sum is σ = 34557600. Its totient is φ = 4128768.

The previous prime is 12697721. The next prime is 12697733. The reversal of 12697728 is 82779621.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×12697728² = 322464592723968, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12697728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12697721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16128 + ... + 16896.

Almost surely, 2^12697728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12697728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17278800).

12697728 is an abundant number, since it is smaller than the sum of its proper divisors (21859872).

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

12697728 is an equidigital number, since it uses as much as digits as its factorization.

12697728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829 (or 817 counting only the distinct ones).

The product of its digits is 84672, while the sum is 42.

The square root of 12697728 is about 3563.3871526962. The cubic root of 12697728 is about 233.2967416542.

The spelling of 12697728 in words is "twelve million, six hundred ninety-seven thousand, seven hundred twenty-eight".