1681424666 has 8 divisors (see below), whose sum is σ = 2523497844. Its totient is φ = 840258720.

The previous prime is 1681424617. The next prime is 1681424681. The reversal of 1681424666 is 6664241861.

It can be written as a sum of positive squares in 2 ways, for example, as 1681410025 + 14641 = 41005^2 + 121^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222155 + ... + 229598.

Almost surely, 2^1681424666 is an apocalyptic number.

1681424666 is a deficient number, since it is larger than the sum of its proper divisors (842073178).

1681424666 is a wasteful number, since it uses less digits than its factorization.

1681424666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453616.

The product of its digits is 331776, while the sum is 44.

The square root of 1681424666 is about 41005.1785266203. The cubic root of 1681424666 is about 1189.1203314632.

The spelling of 1681424666 in words is "one billion, six hundred eighty-one million, four hundred twenty-four thousand, six hundred sixty-six".