666120 has 128 divisors (see below), whose sum is σ = 2499840. Its totient is φ = 138240.

The previous prime is 666119. The next prime is 666139. The reversal of 666120 is 21666.

666120 is nontrivially palindromic in base 11.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 666120.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10890 + ... + 10950.

It is an arithmetic number, because the mean of its divisors is an integer number (19530).

2⁶⁶⁶¹²⁰ is an apocalyptic number.

666120 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 666120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1249920).

666120 is an abundant number, since it is smaller than the sum of its proper divisors (1833720).

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

666120 is a wasteful number, since it uses less digits than its factorization.

666120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 91 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 666120 is about 816.1617486749. The cubic root of 666120 is about 87.3341620780.

Adding to 666120 its reverse (21666), we get a palindrome (687786).

The spelling of 666120 in words is "six hundred sixty-six thousand, one hundred twenty".