666600 has 96 divisors (see below), whose sum is σ = 2276640. Its totient is φ = 160000.

The previous prime is 666599. The next prime is 666607. The reversal of 666600 is 6666.

666600 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

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 (666607) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6550 + ... + 6650.

It is an arithmetic number, because the mean of its divisors is an integer number (23715).

2⁶⁶⁶⁶⁰⁰ is an apocalyptic number.

666600 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 666600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1138320).

666600 is an abundant number, since it is smaller than the sum of its proper divisors (1610040).

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

666600 is a wasteful number, since it uses less digits than its factorization.

666600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 666600 is about 816.4557550780. The cubic root of 666600 is about 87.3551344417.

Multiplying 666600 by its reverse (6666), we get a square (4443555600 = 66660²).

666600 divided by its reverse (6666) gives a square (100 = 10²).

It can be divided in two parts, 66 and 6600, that multiplied together give a square (435600 = 660²).

The spelling of 666600 in words is "six hundred sixty-six thousand, six hundred".