280720 has 60 divisors (see below), whose sum is σ = 742140. Its totient is φ = 98560.

The previous prime is 280717. The next prime is 280729. The reversal of 280720 is 27082.

280720 = T₉ + T₁₀ + ... + T₁₁₈.

It can be written as a sum of positive squares in 2 ways, for example, as 123904 + 156816 = 352^2 + 396^2 .

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 pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9666 + ... + 9694.

It is an arithmetic number, because the mean of its divisors is an integer number (12369).

2²⁸⁰⁷²⁰ is an apocalyptic number.

280720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (371070).

280720 is an abundant number, since it is smaller than the sum of its proper divisors (461420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

280720 is a wasteful number, since it uses less digits than its factorization.

280720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 280720 is about 529.8301614669. The cubic root of 280720 is about 65.4773536301.

It can be divided in two parts, 280 and 720, that added together give a cube (1000 = 10³).

The spelling of 280720 in words is "two hundred eighty thousand, seven hundred twenty".