12728381 has 2 divisors, whose sum is σ = 12728382. Its totient is φ = 12728380.

The previous prime is 12728377. The next prime is 12728389. The reversal of 12728381 is 18382721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9665881 + 3062500 = 3109^2 + 1750^2 .

It is a cyclic number.

It is not a de Polignac number, because 12728381 - 2² = 12728377 is a prime.

It is a super-2 number, since 2×12728381² = 324023365762322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12728389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6364190 + 6364191.

It is an arithmetic number, because the mean of its divisors is an integer number (6364191).

Almost surely, 2^12728381 is an apocalyptic number.

It is an amenable number.

12728381 is a deficient number, since it is larger than the sum of its proper divisors (1).

12728381 is an equidigital number, since it uses as much as digits as its factorization.

12728381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 32.

The square root of 12728381 is about 3567.6856644049. The cubic root of 12728381 is about 233.4843210971.

The spelling of 12728381 in words is "twelve million, seven hundred twenty-eight thousand, three hundred eighty-one".