28008281 has 4 divisors (see below), whose sum is σ = 32009472. Its totient is φ = 24007092.

The previous prime is 28008269. The next prime is 28008307. The reversal of 28008281 is 18280082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28008281 - 2⁶ = 28008217 is a prime.

It is a super-2 number, since 2×28008281² = 1568927609149922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28008251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2000585 + ... + 2000598.

It is an arithmetic number, because the mean of its divisors is an integer number (8002368).

Almost surely, 2^28008281 is an apocalyptic number.

It is an amenable number.

28008281 is a deficient number, since it is larger than the sum of its proper divisors (4001191).

28008281 is an equidigital number, since it uses as much as digits as its factorization.

28008281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4001190.

The product of its (nonzero) digits is 2048, while the sum is 29.

The square root of 28008281 is about 5292.2850452333. The cubic root of 28008281 is about 303.6888299432.

The spelling of 28008281 in words is "twenty-eight million, eight thousand, two hundred eighty-one".