666144 has 60 divisors (see below), whose sum is σ = 1966734. Its totient is φ = 221184.

The previous prime is 666143. The next prime is 666167. The reversal of 666144 is 441666.

It can be written as a sum of positive squares in only one way, i.e., 374544 + 291600 = 612^2 + 540^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666143) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2464 + ... + 2720.

2⁶⁶⁶¹⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (983367).

666144 is an abundant number, since it is smaller than the sum of its proper divisors (1300590).

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

666144 is a wasteful number, since it uses less digits than its factorization.

666144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279 (or 262 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 666144 is about 816.1764515103. The cubic root of 666144 is about 87.3352109354.

It can be divided in two parts, 66 and 6144, that multiplied together give a palindrome (405504).

The spelling of 666144 in words is "six hundred sixty-six thousand, one hundred forty-four".