666600660 has 72 divisors (see below), whose sum is σ = 2205848736. Its totient is φ = 161599680.

The previous prime is 666600647. The next prime is 666600667. The reversal of 666600660 is 66006666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666600667) 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, 166354 + ... + 170313.

It is an arithmetic number, because the mean of its divisors is an integer number (30636788).

Almost surely, 2^666600660 is an apocalyptic number.

666600660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666600660 is an abundant number, since it is smaller than the sum of its proper divisors (1539248076).

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

666600660 is a wasteful number, since it uses less digits than its factorization.

666600660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336693 (or 336688 counting only the distinct ones).

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

The square root of 666600660 is about 25818.6107294719. The cubic root of 666600660 is about 873.5516327175.

It can be divided in two parts, 6 and 66600660, that added together give a palindrome (66600666).

The spelling of 666600660 in words is "six hundred sixty-six million, six hundred thousand, six hundred sixty".