1666685335370 has 24 divisors (see below), whose sum is σ = 3297557599812. Its totient is φ = 606067394240.

The previous prime is 1666685335339. The next prime is 1666685335373. The reversal of 1666685335370 is 735335866661.

It can be written as a sum of positive squares in 2 ways, for example, as 1481159586841 + 185525748529 = 1217029^2 + 430727^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1666685335373) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 688711739 + ... + 688714158.

Almost surely, 2^{1666685335370} is an apocalyptic number.

1666685335370 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1666685335370 is a deficient number, since it is larger than the sum of its proper divisors (1630872264442).

1666685335370 is a wasteful number, since it uses less digits than its factorization.

1666685335370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1377425926 (or 1377425915 counting only the distinct ones).

The product of its (nonzero) digits is 48988800, while the sum is 59.

The spelling of 1666685335370 in words is "one trillion, six hundred sixty-six billion, six hundred eighty-five million, three hundred thirty-five thousand, three hundred seventy".