281680 has 40 divisors (see below), whose sum is σ = 749952. Its totient is φ = 96384.

The previous prime is 281669. The next prime is 281683. The reversal of 281680 is 86182.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281683) by changing a digit.

281680 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 7 ways as a sum of consecutive naturals, for example, 309 + ... + 811.

2²⁸¹⁶⁸⁰ is an apocalyptic number.

281680 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 281680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (374976).

281680 is an abundant number, since it is smaller than the sum of its proper divisors (468272).

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

281680 is a wasteful number, since it uses less digits than its factorization.

281680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 281680 is about 530.7353389402. The cubic root of 281680 is about 65.5519080397.

It can be divided in two parts, 281 and 680, that added together give a square (961 = 31²).

The spelling of 281680 in words is "two hundred eighty-one thousand, six hundred eighty".