28166813 has 2 divisors, whose sum is σ = 28166814. Its totient is φ = 28166812.

The previous prime is 28166791. The next prime is 28166819. The reversal of 28166813 is 31866182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27899524 + 267289 = 5282^2 + 517^2 .

It is a cyclic number.

It is not a de Polignac number, because 28166813 - 2¹⁰ = 28165789 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28166819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14083406 + 14083407.

It is an arithmetic number, because the mean of its divisors is an integer number (14083407).

Almost surely, 2^28166813 is an apocalyptic number.

It is an amenable number.

28166813 is a deficient number, since it is larger than the sum of its proper divisors (1).

28166813 is an equidigital number, since it uses as much as digits as its factorization.

28166813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 35.

The square root of 28166813 is about 5307.2415622430. The cubic root of 28166813 is about 304.2607304082.

It can be divided in two parts, 28 and 166813, that multiplied together give a palindrome (4670764).

The spelling of 28166813 in words is "twenty-eight million, one hundred sixty-six thousand, eight hundred thirteen".