28127909 has 2 divisors, whose sum is σ = 28127910. Its totient is φ = 28127908.

The previous prime is 28127899. The next prime is 28127921. The reversal of 28127909 is 90972182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19775809 + 8352100 = 4447^2 + 2890^2 .

It is a cyclic number.

It is not a de Polignac number, because 28127909 - 2²⁴ = 11350693 is a prime.

It is equal to p_1748882 and since 28127909 and 1748882 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28127959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14063954 + 14063955.

It is an arithmetic number, because the mean of its divisors is an integer number (14063955).

Almost surely, 2^28127909 is an apocalyptic number.

It is an amenable number.

28127909 is a deficient number, since it is larger than the sum of its proper divisors (1).

28127909 is an equidigital number, since it uses as much as digits as its factorization.

28127909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 28127909 is about 5303.5751149578. The cubic root of 28127909 is about 304.1205842324.

The spelling of 28127909 in words is "twenty-eight million, one hundred twenty-seven thousand, nine hundred nine".