1666685000 has 40 divisors (see below), whose sum is σ = 3905054670. Its totient is φ = 666672000.

The previous prime is 1666684993. The next prime is 1666685021. The reversal of 1666685000 is 5866661.

It can be written as a sum of positive squares in 5 ways, for example, as 2208196 + 1664476804 = 1486^2 + 40798^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 161669 + ... + 171668.

Almost surely, 2^1666685000 is an apocalyptic number.

1666685000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666685000 is an abundant number, since it is smaller than the sum of its proper divisors (2238369670).

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

1666685000 is an equidigital number, since it uses as much as digits as its factorization.

1666685000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333363 (or 333344 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 1666685000 is about 40825.0535823286. The cubic root of 1666685000 is about 1185.6354487948.

The spelling of 1666685000 in words is "one billion, six hundred sixty-six million, six hundred eighty-five thousand".