1666516666 has 8 divisors (see below), whose sum is σ = 2500816500. Its totient is φ = 832911168.

The previous prime is 1666516583. The next prime is 1666516699. The reversal of 1666516666 is 6666156661.

It can be written as a sum of positive squares in 2 ways, for example, as 1598800225 + 67716441 = 39985^2 + 8229^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167541 + ... + 177208.

Almost surely, 2^1666516666 is an apocalyptic number.

1666516666 is a deficient number, since it is larger than the sum of its proper divisors (834299834).

1666516666 is a wasteful number, since it uses less digits than its factorization.

1666516666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347168.

The product of its digits is 1399680, while the sum is 49.

The square root of 1666516666 is about 40822.9918795769. The cubic root of 1666516666 is about 1185.5955313384.

The spelling of 1666516666 in words is "one billion, six hundred sixty-six million, five hundred sixteen thousand, six hundred sixty-six".