287920 has 40 divisors (see below), whose sum is σ = 691920. Its totient is φ = 111360.

The previous prime is 287887. The next prime is 287921. The reversal of 287920 is 29782.

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

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (287921) 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, 4690 + ... + 4750.

It is an arithmetic number, because the mean of its divisors is an integer number (17298).

2²⁸⁷⁹²⁰ is an apocalyptic number.

287920 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 287920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345960).

287920 is an abundant number, since it is smaller than the sum of its proper divisors (404000).

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

287920 is a wasteful number, since it uses less digits than its factorization.

287920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 287920 is about 536.5817738239. The cubic root of 287920 is about 66.0324297315.

The spelling of 287920 in words is "two hundred eighty-seven thousand, nine hundred twenty".