28717109 has 2 divisors, whose sum is σ = 28717110. Its totient is φ = 28717108.

The previous prime is 28717103. The next prime is 28717123. The reversal of 28717109 is 90171782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28654609 + 62500 = 5353^2 + 250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28717109 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28717103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14358554 + 14358555.

It is an arithmetic number, because the mean of its divisors is an integer number (14358555).

Almost surely, 2^28717109 is an apocalyptic number.

It is an amenable number.

28717109 is a deficient number, since it is larger than the sum of its proper divisors (1).

28717109 is an equidigital number, since it uses as much as digits as its factorization.

28717109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 28717109 is about 5358.8346680972. The cubic root of 28717109 is about 306.2294155816.

The spelling of 28717109 in words is "twenty-eight million, seven hundred seventeen thousand, one hundred nine".