666180 has 36 divisors (see below), whose sum is σ = 2021292. Its totient is φ = 177600.

The previous prime is 666173. The next prime is 666187. The reversal of 666180 is 81666.

It is an interprime number because it is at equal distance from previous prime (666173) and next prime (666187).

It can be written as a sum of positive squares in 2 ways, for example, as 254016 + 412164 = 504^2 + 642^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (666187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1671 + ... + 2030.

It is an arithmetic number, because the mean of its divisors is an integer number (56147).

2⁶⁶⁶¹⁸⁰ is an apocalyptic number.

666180 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666180 is an abundant number, since it is smaller than the sum of its proper divisors (1355112).

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

666180 is a wasteful number, since it uses less digits than its factorization.

666180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3716 (or 3711 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 666180 is about 816.1985052669. The cubic root of 666180 is about 87.3367841743.

The spelling of 666180 in words is "six hundred sixty-six thousand, one hundred eighty".