28908281 has 2 divisors, whose sum is σ = 28908282. Its totient is φ = 28908280.

The previous prime is 28908251. The next prime is 28908287. The reversal of 28908281 is 18280982.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22231225 + 6677056 = 4715^2 + 2584^2 .

It is a cyclic number.

It is not a de Polignac number, because 28908281 - 2¹⁰ = 28907257 is a prime.

It is a super-2 number, since 2×28908281² = 1671377420749922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28908287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14454140 + 14454141.

It is an arithmetic number, because the mean of its divisors is an integer number (14454141).

Almost surely, 2^28908281 is an apocalyptic number.

It is an amenable number.

28908281 is a deficient number, since it is larger than the sum of its proper divisors (1).

28908281 is an equidigital number, since it uses as much as digits as its factorization.

28908281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 28908281 is about 5376.6421677475. The cubic root of 28908281 is about 306.9074441496.

The spelling of 28908281 in words is "twenty-eight million, nine hundred eight thousand, two hundred eighty-one".