28687117 has 2 divisors, whose sum is σ = 28687118. Its totient is φ = 28687116.

The previous prime is 28687097. The next prime is 28687123. The reversal of 28687117 is 71178682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24790441 + 3896676 = 4979^2 + 1974^2 .

It is a cyclic number.

It is not a de Polignac number, because 28687117 - 2⁷ = 28686989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28687117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28687717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14343558 + 14343559.

It is an arithmetic number, because the mean of its divisors is an integer number (14343559).

Almost surely, 2^28687117 is an apocalyptic number.

It is an amenable number.

28687117 is a deficient number, since it is larger than the sum of its proper divisors (1).

28687117 is an equidigital number, since it uses as much as digits as its factorization.

28687117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37632, while the sum is 40.

The square root of 28687117 is about 5356.0355674697. The cubic root of 28687117 is about 306.1227703075.

The spelling of 28687117 in words is "twenty-eight million, six hundred eighty-seven thousand, one hundred seventeen".