280729 has 2 divisors, whose sum is σ = 280730. Its totient is φ = 280728.

The previous prime is 280717. The next prime is 280751. The reversal of 280729 is 927082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176400 + 104329 = 420^2 + 323^2 .

It is a cyclic number.

It is not a de Polignac number, because 280729 - 2⁵ = 280697 is a prime.

It is a plaindrome in base 16.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 280697 and 280706.

It is not a weakly prime, because it can be changed into another prime (280759) 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, 140364 + 140365.

It is an arithmetic number, because the mean of its divisors is an integer number (140365).

2²⁸⁰⁷²⁹ is an apocalyptic number.

It is an amenable number.

280729 is a deficient number, since it is larger than the sum of its proper divisors (1).

280729 is an equidigital number, since it uses as much as digits as its factorization.

280729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 280729 is about 529.8386546865. The cubic root of 280729 is about 65.4780533664.

The spelling of 280729 in words is "two hundred eighty thousand, seven hundred twenty-nine".