287240 has 32 divisors (see below), whose sum is σ = 665280. Its totient is φ = 111552.

The previous prime is 287239. The next prime is 287251. The reversal of 287240 is 42782.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1637 + ... + 1803.

It is an arithmetic number, because the mean of its divisors is an integer number (20790).

2²⁸⁷²⁴⁰ is an apocalyptic number.

287240 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 287240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332640).

287240 is an abundant number, since it is smaller than the sum of its proper divisors (378040).

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

287240 is a wasteful number, since it uses less digits than its factorization.

287240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 287240 is about 535.9477586482. The cubic root of 287240 is about 65.9804043448.

The spelling of 287240 in words is "two hundred eighty-seven thousand, two hundred forty".