280404 has 18 divisors (see below), whose sum is σ = 708890. Its totient is φ = 93456.

The previous prime is 280373. The next prime is 280409. The reversal of 280404 is 404082.

It is a happy number.

280404 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 248004 + 32400 = 498^2 + 180^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

280404 is a modest number, since divided by 404 gives 28 as remainder.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280404.

It is not an unprimeable number, because it can be changed into a prime (280409) by changing a digit.

280404 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3859 + ... + 3930.

2²⁸⁰⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

280404 is an abundant number, since it is smaller than the sum of its proper divisors (428486).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

280404 is a wasteful number, since it uses less digits than its factorization.

280404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7799 (or 7794 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 280404 is about 529.5318687294. The cubic root of 280404 is about 65.4527756255.

Adding to 280404 its reverse (404082), we get a palindrome (684486).

The spelling of 280404 in words is "two hundred eighty thousand, four hundred four".