28001 has 2 divisors, whose sum is σ = 28002. Its totient is φ = 28000.

The previous prime is 27997. The next prime is 28019. The reversal of 28001 is 10082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25600 + 2401 = 160^2 + 49^2 .

It is a cyclic number.

It is not a de Polignac number, because 28001 - 2² = 27997 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 6.

It is a nialpdrome in base 8.

It is not a weakly prime, because it can be changed into another prime (28031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14000 + 14001.

It is an arithmetic number, because the mean of its divisors is an integer number (14001).

2²⁸⁰⁰¹ is an apocalyptic number.

It is an amenable number.

28001 is a deficient number, since it is larger than the sum of its proper divisors (1).

28001 is an equidigital number, since it uses as much as digits as its factorization.

28001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 28001 is about 167.3349933517. The cubic root of 28001 is about 30.3662512131.

Adding to 28001 its reverse (10082), we get a palindrome (38083).

The spelling of 28001 in words is "twenty-eight thousand, one".