280397 has 4 divisors (see below), whose sum is σ = 301980. Its totient is φ = 258816.

The previous prime is 280373. The next prime is 280409. The reversal of 280397 is 793082.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 793082 = 2 ⋅396541.

It can be written as a sum of positive squares in 2 ways, for example, as 21316 + 259081 = 146^2 + 509^2 .

It is a cyclic number.

It is not a de Polignac number, because 280397 - 2¹⁴ = 264013 is a prime.

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 280397.

It is not an unprimeable number, because it can be changed into a prime (280327) 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, 10772 + ... + 10797.

It is an arithmetic number, because the mean of its divisors is an integer number (75495).

2²⁸⁰³⁹⁷ is an apocalyptic number.

It is an amenable number.

280397 is a deficient number, since it is larger than the sum of its proper divisors (21583).

280397 is a wasteful number, since it uses less digits than its factorization.

280397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21582.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 280397 is about 529.5252590765. The cubic root of 280397 is about 65.4522309671.

The spelling of 280397 in words is "two hundred eighty thousand, three hundred ninety-seven".