865600 has 42 divisors (see below), whose sum is σ = 2133854. Its totient is φ = 345600.

The previous prime is 865597. The next prime is 865609. The reversal of 865600 is 6568.

It can be written as a sum of positive squares in 3 ways, for example, as 33856 + 831744 = 184^2 + 912^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865609) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1330 + ... + 1870.

2⁸⁶⁵⁶⁰⁰ is an apocalyptic number.

865600 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 865600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1066927).

865600 is an abundant number, since it is smaller than the sum of its proper divisors (1268254).

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

865600 is a wasteful number, since it uses less digits than its factorization.

865600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 865600 is about 930.3762679690. The cubic root of 865600 is about 95.3028194952.

It can be divided in two parts, 8 and 65600, that multiplied together give a triangular number (524800 = T₁₀₂₄).

The spelling of 865600 in words is "eight hundred sixty-five thousand, six hundred".