27808813 has 2 divisors, whose sum is σ = 27808814. Its totient is φ = 27808812.

The previous prime is 27808789. The next prime is 27808853. The reversal of 27808813 is 31880872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22486564 + 5322249 = 4742^2 + 2307^2 .

It is a cyclic number.

It is not a de Polignac number, because 27808813 - 2¹³ = 27800621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27808853) 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, 13904406 + 13904407.

It is an arithmetic number, because the mean of its divisors is an integer number (13904407).

Almost surely, 2^27808813 is an apocalyptic number.

It is an amenable number.

27808813 is a deficient number, since it is larger than the sum of its proper divisors (1).

27808813 is an equidigital number, since it uses as much as digits as its factorization.

27808813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 27808813 is about 5273.4062047220. The cubic root of 27808813 is about 302.9661796422.

The spelling of 27808813 in words is "twenty-seven million, eight hundred eight thousand, eight hundred thirteen".