666060660 has 72 divisors (see below), whose sum is σ = 2040443496. Its totient is φ = 175852800.

The previous prime is 666060631. The next prime is 666060677. The reversal of 666060660 is 66060666.

It can be written as a sum of positive squares in 4 ways, for example, as 176943204 + 489117456 = 13302^2 + 22116^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 139 + ... + 36498.

It is an arithmetic number, because the mean of its divisors is an integer number (28339493).

Almost surely, 2^666060660 is an apocalyptic number.

666060660 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 666060660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1020221748).

666060660 is an abundant number, since it is smaller than the sum of its proper divisors (1374382836).

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

666060660 is a wasteful number, since it uses less digits than its factorization.

666060660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36753 (or 36748 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 666060660 is about 25808.1510379957. The cubic root of 666060660 is about 873.3156866987.

It can be divided in two parts, 6660606 and 60, that added together give a palindrome (6660666).

The spelling of 666060660 in words is "six hundred sixty-six million, sixty thousand, six hundred sixty".