28081117 has 2 divisors, whose sum is σ = 28081118. Its totient is φ = 28081116.

The previous prime is 28081099. The next prime is 28081153. The reversal of 28081117 is 71118082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27994681 + 86436 = 5291^2 + 294^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28081117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28091117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14040558 + 14040559.

It is an arithmetic number, because the mean of its divisors is an integer number (14040559).

Almost surely, 2^28081117 is an apocalyptic number.

It is an amenable number.

28081117 is a deficient number, since it is larger than the sum of its proper divisors (1).

28081117 is an equidigital number, since it uses as much as digits as its factorization.

28081117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 28.

The square root of 28081117 is about 5299.1619148692. The cubic root of 28081117 is about 303.9518513599.

Adding to 28081117 its reverse (71118082), we get a palindrome (99199199).

The spelling of 28081117 in words is "twenty-eight million, eighty-one thousand, one hundred seventeen".