280001 has 2 divisors, whose sum is σ = 280002. Its totient is φ = 280000.

The previous prime is 279991. The next prime is 280009. The reversal of 280001 is 100082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201601 + 78400 = 449^2 + 280^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-280001 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140000 + 140001.

It is an arithmetic number, because the mean of its divisors is an integer number (140001).

2²⁸⁰⁰⁰¹ is an apocalyptic number.

It is an amenable number.

280001 is a deficient number, since it is larger than the sum of its proper divisors (1).

280001 is an equidigital number, since it uses as much as digits as its factorization.

280001 is an odious number, because the sum of its binary digits is odd.

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

The square root of 280001 is about 529.1512071233. The cubic root of 280001 is about 65.4214040862.

Adding to 280001 its reverse (100082), we get a palindrome (380083).

The spelling of 280001 in words is "two hundred eighty thousand, one".