280491 has 4 divisors (see below), whose sum is σ = 373992. Its totient is φ = 186992.

The previous prime is 280487. The next prime is 280499. The reversal of 280491 is 194082.

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

It is a cyclic number.

It is not a de Polignac number, because 280491 - 2² = 280487 is a prime.

It is a D-number.

It is a plaindrome in base 16.

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (280499) 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, 46746 + ... + 46751.

It is an arithmetic number, because the mean of its divisors is an integer number (93498).

2²⁸⁰⁴⁹¹ is an apocalyptic number.

280491 is a deficient number, since it is larger than the sum of its proper divisors (93501).

280491 is an equidigital number, since it uses as much as digits as its factorization.

280491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93500.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 280491 is about 529.6140103887. The cubic root of 280491 is about 65.4595441960.

The spelling of 280491 in words is "two hundred eighty thousand, four hundred ninety-one".