289640 has 32 divisors (see below), whose sum is σ = 703080. Its totient is φ = 106752.

The previous prime is 289637. The next prime is 289643. The reversal of 289640 is 46982.

It is an interprime number because it is at equal distance from previous prime (289637) and next prime (289643).

It can be written as a sum of positive squares in 4 ways, for example, as 111556 + 178084 = 334^2 + 422^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (289643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 242 + ... + 798.

2²⁸⁹⁶⁴⁰ is an apocalyptic number.

289640 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 289640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (351540).

289640 is an abundant number, since it is smaller than the sum of its proper divisors (413440).

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

289640 is a wasteful number, since it uses less digits than its factorization.

289640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 581 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 289640 is about 538.1821253070. The cubic root of 289640 is about 66.1636587350.

It can be divided in two parts, 289 and 640, that added together give a palindrome (929).

The spelling of 289640 in words is "two hundred eighty-nine thousand, six hundred forty".