12728581 has 2 divisors, whose sum is σ = 12728582. Its totient is φ = 12728580.

The previous prime is 12728567. The next prime is 12728609. The reversal of 12728581 is 18582721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12285025 + 443556 = 3505^2 + 666^2 .

It is a cyclic number.

It is not a de Polignac number, because 12728581 - 2⁵ = 12728549 is a prime.

It is a super-2 number, since 2×12728581² = 324033548547122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12728561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6364290 + 6364291.

It is an arithmetic number, because the mean of its divisors is an integer number (6364291).

Almost surely, 2^12728581 is an apocalyptic number.

It is an amenable number.

12728581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12728581 is an equidigital number, since it uses as much as digits as its factorization.

12728581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8960, while the sum is 34.

The square root of 12728581 is about 3567.7136936699. The cubic root of 12728581 is about 233.4855439973.

The spelling of 12728581 in words is "twelve million, seven hundred twenty-eight thousand, five hundred eighty-one".