280749 has 16 divisors (see below), whose sum is σ = 443520. Its totient is φ = 154560.

The previous prime is 280729. The next prime is 280751. The reversal of 280749 is 947082.

It is not a de Polignac number, because 280749 - 2⁵ = 280717 is a prime.

280749 is a lucky number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 379 + ... + 839.

It is an arithmetic number, because the mean of its divisors is an integer number (27720).

2²⁸⁰⁷⁴⁹ is an apocalyptic number.

280749 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

280749 is a deficient number, since it is larger than the sum of its proper divisors (162771).

280749 is a wasteful number, since it uses less digits than its factorization.

280749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 280749 is about 529.8575280205. The cubic root of 280749 is about 65.4796082823.

The spelling of 280749 in words is "two hundred eighty thousand, seven hundred forty-nine".