280403 has 4 divisors (see below), whose sum is σ = 286968. Its totient is φ = 273840.

The previous prime is 280373. The next prime is 280409. The reversal of 280403 is 304082.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 304082 = 2 ⋅152041.

It is a cyclic number.

It is not a de Polignac number, because 280403 - 2⁶ = 280339 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280403.

It is not an unprimeable number, because it can be changed into a prime (280409) 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, 3218 + ... + 3303.

It is an arithmetic number, because the mean of its divisors is an integer number (71742).

2²⁸⁰⁴⁰³ is an apocalyptic number.

280403 is a deficient number, since it is larger than the sum of its proper divisors (6565).

280403 is an equidigital number, since it uses as much as digits as its factorization.

280403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6564.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 280403 is about 529.5309244983. The cubic root of 280403 is about 65.4526978177.

Adding to 280403 its reverse (304082), we get a palindrome (584485).

The spelling of 280403 in words is "two hundred eighty thousand, four hundred three".