85440 has 56 divisors (see below), whose sum is σ = 274320. Its totient is φ = 22528.

The previous prime is 85439. The next prime is 85447. The reversal of 85440 is 4458.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85447) 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, 916 + ... + 1004.

2⁸⁵⁴⁴⁰ is an apocalyptic number.

85440 is a gapful number since it is divisible by the number (80) 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 85440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137160).

85440 is an abundant number, since it is smaller than the sum of its proper divisors (188880).

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

85440 is a wasteful number, since it uses less digits than its factorization.

85440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 85440 is about 292.3012145031. The cubic root of 85440 is about 44.0440330542.

Adding to 85440 its reverse (4458), we get a palindrome (89898).

It can be divided in two parts, 85 and 440, that added together give a palindrome (525).

The spelling of 85440 in words is "eighty-five thousand, four hundred forty".