28285181 has 2 divisors, whose sum is σ = 28285182. Its totient is φ = 28285180.

The previous prime is 28285177. The next prime is 28285217. The reversal of 28285181 is 18158282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22477081 + 5808100 = 4741^2 + 2410^2 .

It is a cyclic number.

It is not a de Polignac number, because 28285181 - 2² = 28285177 is a prime.

It is a super-2 number, since 2×28285181² = 1600102928405522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28285171) 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, 14142590 + 14142591.

It is an arithmetic number, because the mean of its divisors is an integer number (14142591).

Almost surely, 2^28285181 is an apocalyptic number.

It is an amenable number.

28285181 is a deficient number, since it is larger than the sum of its proper divisors (1).

28285181 is an equidigital number, since it uses as much as digits as its factorization.

28285181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10240, while the sum is 35.

The square root of 28285181 is about 5318.3814267125. The cubic root of 28285181 is about 304.6863424247.

The spelling of 28285181 in words is "twenty-eight million, two hundred eighty-five thousand, one hundred eighty-one".