28283681 has 2 divisors, whose sum is σ = 28283682. Its totient is φ = 28283680.

The previous prime is 28283677. The next prime is 28283683. The reversal of 28283681 is 18638282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26368225 + 1915456 = 5135^2 + 1384^2 .

It is a cyclic number.

It is not a de Polignac number, because 28283681 - 2² = 28283677 is a prime.

It is a super-2 number, since 2×28283681² = 1599933221819522, which contains 22 as substring.

Together with 28283683, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1757990 and since 28283681 and 1757990 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (28283683) 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, 14141840 + 14141841.

It is an arithmetic number, because the mean of its divisors is an integer number (14141841).

Almost surely, 2^28283681 is an apocalyptic number.

It is an amenable number.

28283681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28283681 is an equidigital number, since it uses as much as digits as its factorization.

28283681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36864, while the sum is 38.

The square root of 28283681 is about 5318.2404044947. The cubic root of 28283681 is about 304.6809563583.

The spelling of 28283681 in words is "twenty-eight million, two hundred eighty-three thousand, six hundred eighty-one".