1668666688 has 56 divisors (see below), whose sum is σ = 3775767912. Its totient is φ = 724844544.

The previous prime is 1668666683. The next prime is 1668666689. The reversal of 1668666688 is 8866668661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 107584 + 1668559104 = 328^2 + 40848^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668666683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44845 + ... + 73132.

It is an arithmetic number, because the mean of its divisors is an integer number (67424427).

Almost surely, 2^1668666688 is an apocalyptic number.

It is an amenable number.

1668666688 is an abundant number, since it is smaller than the sum of its proper divisors (2107101224).

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

1668666688 is a wasteful number, since it uses less digits than its factorization.

1668666688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118019 (or 118009 counting only the distinct ones).

The product of its digits is 23887872, while the sum is 61.

The square root of 1668666688 is about 40849.3168608730. The cubic root of 1668666688 is about 1186.1051694173.

The spelling of 1668666688 in words is "one billion, six hundred sixty-eight million, six hundred sixty-six thousand, six hundred eighty-eight".