28840117 has 2 divisors, whose sum is σ = 28840118. Its totient is φ = 28840116.

The previous prime is 28840099. The next prime is 28840121. The reversal of 28840117 is 71104882.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28313041 + 527076 = 5321^2 + 726^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28840117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28840127) 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, 14420058 + 14420059.

It is an arithmetic number, because the mean of its divisors is an integer number (14420059).

Almost surely, 2^28840117 is an apocalyptic number.

It is an amenable number.

28840117 is a deficient number, since it is larger than the sum of its proper divisors (1).

28840117 is an equidigital number, since it uses as much as digits as its factorization.

28840117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 28840117 is about 5370.2995260972. The cubic root of 28840117 is about 306.6660311634. Note that the first 3 decimals are identical.

Adding to 28840117 its reverse (71104882), we get a palindrome (99944999).

The spelling of 28840117 in words is "twenty-eight million, eight hundred forty thousand, one hundred seventeen".