1999646668 has 12 divisors (see below), whose sum is σ = 3504794832. Its totient is φ = 998276720.

The previous prime is 1999646653. The next prime is 1999646669. The reversal of 1999646668 is 8666469991.

It is not an unprimeable number, because it can be changed into a prime (1999646669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 383743 + ... + 388918.

It is an arithmetic number, because the mean of its divisors is an integer number (292066236).

Almost surely, 2^1999646668 is an apocalyptic number.

It is an amenable number.

1999646668 is a deficient number, since it is larger than the sum of its proper divisors (1505148164).

1999646668 is a wasteful number, since it uses less digits than its factorization.

1999646668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773312 (or 773310 counting only the distinct ones).

The product of its digits is 30233088, while the sum is 64.

The square root of 1999646668 is about 44717.4090036532. The cubic root of 1999646668 is about 1259.8468504545.

The spelling of 1999646668 in words is "one billion, nine hundred ninety-nine million, six hundred forty-six thousand, six hundred sixty-eight".