280018 has 4 divisors (see below), whose sum is σ = 420030. Its totient is φ = 140008.

The previous prime is 280013. The next prime is 280031. The reversal of 280018 is 810082.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 237169 + 42849 = 487^2 + 207^2 .

It is a junction number, because it is equal to n+sod(n) for n = 279977 and 280004.

It is not an unprimeable number, because it can be changed into a prime (280013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70003 + ... + 70006.

2²⁸⁰⁰¹⁸ is an apocalyptic number.

280018 is a deficient number, since it is larger than the sum of its proper divisors (140012).

280018 is a wasteful number, since it uses less digits than its factorization.

280018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140011.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 280018 is about 529.1672703409. The cubic root of 280018 is about 65.4227280593.

The spelling of 280018 in words is "two hundred eighty thousand, eighteen".