28186913 has 2 divisors, whose sum is σ = 28186914. Its totient is φ = 28186912.

The previous prime is 28186889. The next prime is 28186919. The reversal of 28186913 is 31968182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22771984 + 5414929 = 4772^2 + 2327^2 .

It is a cyclic number.

It is not a de Polignac number, because 28186913 - 2⁶ = 28186849 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28186919) 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, 14093456 + 14093457.

It is an arithmetic number, because the mean of its divisors is an integer number (14093457).

Almost surely, 2^28186913 is an apocalyptic number.

It is an amenable number.

28186913 is a deficient number, since it is larger than the sum of its proper divisors (1).

28186913 is an equidigital number, since it uses as much as digits as its factorization.

28186913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 38.

The square root of 28186913 is about 5309.1348636101. The cubic root of 28186913 is about 304.3330872694. Note that the first 3 decimals are identical.

The spelling of 28186913 in words is "twenty-eight million, one hundred eighty-six thousand, nine hundred thirteen".