1666603660 has 12 divisors (see below), whose sum is σ = 3499867728. Its totient is φ = 666641456.

The previous prime is 1666603637. The next prime is 1666603663. The reversal of 1666603660 is 663066661.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1666603663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41665072 + ... + 41665111.

It is an arithmetic number, because the mean of its divisors is an integer number (291655644).

Almost surely, 2^1666603660 is an apocalyptic number.

1666603660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666603660 is an abundant number, since it is smaller than the sum of its proper divisors (1833264068).

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

1666603660 is a wasteful number, since it uses less digits than its factorization.

1666603660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83330192 (or 83330190 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 40.

The square root of 1666603660 is about 40824.0573681745. The cubic root of 1666603660 is about 1185.6161607757.

The spelling of 1666603660 in words is "one billion, six hundred sixty-six million, six hundred three thousand, six hundred sixty".