660240 has 120 divisors (see below), whose sum is σ = 2553408. Its totient is φ = 149760.

The previous prime is 660227. The next prime is 660241. The reversal of 660240 is 42066.

660240 is a `hidden beast` number, since 660 + 2 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is not an unprimeable number, because it can be changed into a prime (660241) by changing a digit.

660240 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4975 + ... + 5105.

2⁶⁶⁰²⁴⁰ is an apocalyptic number.

660240 is a gapful number since it is divisible by the number (60) 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 660240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1276704).

660240 is an abundant number, since it is smaller than the sum of its proper divisors (1893168).

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

660240 is a wasteful number, since it uses less digits than its factorization.

660240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 660240 is about 812.5515368270. The cubic root of 660240 is about 87.0764290724.

It can be divided in two parts, 660 and 240, that added together give a square (900 = 30²).

The spelling of 660240 in words is "six hundred sixty thousand, two hundred forty".