280109 has 4 divisors (see below), whose sum is σ = 296604. Its totient is φ = 263616.

The previous prime is 280103. The next prime is 280121. The reversal of 280109 is 901082.

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

It can be written as a sum of positive squares in 2 ways, for example, as 157609 + 122500 = 397^2 + 350^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-280109 is a prime.

It is a super-2 number, since 2×280109² = 156922103762, which contains 22 as substring.

It is a Duffinian number.

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 280109.

It is not an unprimeable number, because it can be changed into a prime (280103) 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, 8222 + ... + 8255.

It is an arithmetic number, because the mean of its divisors is an integer number (74151).

2²⁸⁰¹⁰⁹ is an apocalyptic number.

It is an amenable number.

280109 is a deficient number, since it is larger than the sum of its proper divisors (16495).

280109 is a wasteful number, since it uses less digits than its factorization.

280109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16494.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 280109 is about 529.2532475101. The cubic root of 280109 is about 65.4298142983.

The spelling of 280109 in words is "two hundred eighty thousand, one hundred nine".