280306 has 8 divisors (see below), whose sum is σ = 452844. Its totient is φ = 129360.

The previous prime is 280303. The next prime is 280321. The reversal of 280306 is 603082.

It can be written as a sum of positive squares in 2 ways, for example, as 255025 + 25281 = 505^2 + 159^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (280303) 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, 5365 + ... + 5416.

2²⁸⁰³⁰⁶ is an apocalyptic number.

280306 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

280306 is a deficient number, since it is larger than the sum of its proper divisors (172538).

280306 is a wasteful number, since it uses less digits than its factorization.

280306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10796.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 280306 is about 529.4393260800. The cubic root of 280306 is about 65.4451495819.

Adding to 280306 its reverse (603082), we get a palindrome (883388).

It can be divided in two parts, 2 and 80306, that added together give a palindrome (80308).

The spelling of 280306 in words is "two hundred eighty thousand, three hundred six".