280868 has 18 divisors (see below), whose sum is σ = 572166. Its totient is φ = 120288.

The previous prime is 280859. The next prime is 280871. The reversal of 280868 is 868082.

It can be written as a sum of positive squares in only one way, i.e., 268324 + 12544 = 518^2 + 112^2 .

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280868.

It is an unprimeable number.

280868 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 521 + ... + 912.

It is an arithmetic number, because the mean of its divisors is an integer number (31787).

2²⁸⁰⁸⁶⁸ is an apocalyptic number.

280868 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

280868 is an abundant number, since it is smaller than the sum of its proper divisors (291298).

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

280868 is a wasteful number, since it uses less digits than its factorization.

280868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451 (or 1442 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 280868 is about 529.9698104609. The cubic root of 280868 is about 65.4888585055.

Adding to 280868 its sum of digits (32), we get a square (280900 = 530²).

The spelling of 280868 in words is "two hundred eighty thousand, eight hundred sixty-eight".