660000 has 120 divisors (see below), whose sum is σ = 2361744. Its totient is φ = 160000.

The previous prime is 659999. The next prime is 660001. The reversal of 660000 is 66.

It is an interprime number because it is at equal distance from previous prime (659999) and next prime (660001).

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

It is a hoax number, since the sum of its digits (12) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (12).

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

It is an Ulam number.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (660001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 59995 + ... + 60005.

2⁶⁶⁰⁰⁰⁰ is an apocalyptic number.

660000 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 660000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1180872).

660000 is an abundant number, since it is smaller than the sum of its proper divisors (1701744).

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

660000 is a wasteful number, since it uses less digits than its factorization.

660000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 660000 is about 812.4038404636. The cubic root of 660000 is about 87.0658769117.

Adding to 660000 its reverse (66), we get a palindrome (660066).

Multiplying 660000 by its reverse (66), we get a square (43560000 = 6600²).

660000 divided by its reverse (66) gives a 4-th power (10000 = 10⁴).

It can be divided in two parts, 6 and 60000, that multiplied together give a square (360000 = 600²).

The spelling of 660000 in words is "six hundred sixty thousand".