868640 has 48 divisors (see below), whose sum is σ = 2109240. Its totient is φ = 337920.

The previous prime is 868639. The next prime is 868663. The reversal of 868640 is 46868.

It can be written as a sum of positive squares in 4 ways, for example, as 309136 + 559504 = 556^2 + 748^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 868597 and 868606.

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, 9716 + ... + 9804.

2⁸⁶⁸⁶⁴⁰ is an apocalyptic number.

868640 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 868640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1054620).

868640 is an abundant number, since it is smaller than the sum of its proper divisors (1240600).

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

868640 is a wasteful number, since it uses less digits than its factorization.

868640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 868640 is about 932.0085836515. The cubic root of 868640 is about 95.4142574434.

The spelling of 868640 in words is "eight hundred sixty-eight thousand, six hundred forty".