28686817 has 2 divisors, whose sum is σ = 28686818. Its totient is φ = 28686816.

The previous prime is 28686809. The next prime is 28686857. The reversal of 28686817 is 71868682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28686736 + 81 = 5356^2 + 9^2 .

It is a cyclic number.

It is not a de Polignac number, because 28686817 - 2³ = 28686809 is a prime.

It is not a weakly prime, because it can be changed into another prime (28686857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14343408 + 14343409.

It is an arithmetic number, because the mean of its divisors is an integer number (14343409).

Almost surely, 2^28686817 is an apocalyptic number.

It is an amenable number.

28686817 is a deficient number, since it is larger than the sum of its proper divisors (1).

28686817 is an equidigital number, since it uses as much as digits as its factorization.

28686817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 258048, while the sum is 46.

The square root of 28686817 is about 5356.0075616078. The cubic root of 28686817 is about 306.1217031949.

The spelling of 28686817 in words is "twenty-eight million, six hundred eighty-six thousand, eight hundred seventeen".