865540 has 24 divisors (see below), whose sum is σ = 1958040. Its totient is φ = 319488.

The previous prime is 865537. The next prime is 865577. The reversal of 865540 is 45568.

It can be written as a sum of positive squares in 4 ways, for example, as 4356 + 861184 = 66^2 + 928^2 .

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 a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 865499 and 865508.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1405 + ... + 1924.

It is an arithmetic number, because the mean of its divisors is an integer number (81585).

2⁸⁶⁵⁵⁴⁰ is an apocalyptic number.

It is an amenable number.

865540 is an abundant number, since it is smaller than the sum of its proper divisors (1092500).

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

865540 is a wasteful number, since it uses less digits than its factorization.

865540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3351 (or 3349 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 865540 is about 930.3440223917. The cubic root of 865540 is about 95.3006174383.

Adding to 865540 its sum of digits (28), we get a palindrome (865568).

The spelling of 865540 in words is "eight hundred sixty-five thousand, five hundred forty".