281240 has 32 divisors (see below), whose sum is σ = 648000. Its totient is φ = 109824.

The previous prime is 281233. The next prime is 281243. The reversal of 281240 is 42182.

281240 = 6² + 7² + ... + 94².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3116 + ... + 3204.

It is an arithmetic number, because the mean of its divisors is an integer number (20250).

2²⁸¹²⁴⁰ is an apocalyptic number.

281240 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 281240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324000).

281240 is an abundant number, since it is smaller than the sum of its proper divisors (366760).

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

281240 is a wasteful number, since it uses less digits than its factorization.

281240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 281240 is about 530.3206577157. The cubic root of 281240 is about 65.5177583301.

The spelling of 281240 in words is "two hundred eighty-one thousand, two hundred forty".