28507109 has 2 divisors, whose sum is σ = 28507110. Its totient is φ = 28507108.

The previous prime is 28507033. The next prime is 28507111. The reversal of 28507109 is 90170582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28058209 + 448900 = 5297^2 + 670^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28507109 is a prime.

Together with 28507111, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28507159) 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, 14253554 + 14253555.

It is an arithmetic number, because the mean of its divisors is an integer number (14253555).

Almost surely, 2^28507109 is an apocalyptic number.

It is an amenable number.

28507109 is a deficient number, since it is larger than the sum of its proper divisors (1).

28507109 is an equidigital number, since it uses as much as digits as its factorization.

28507109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 28507109 is about 5339.2049033541. The cubic root of 28507109 is about 305.4811325865.

The spelling of 28507109 in words is "twenty-eight million, five hundred seven thousand, one hundred nine".