1660066666 has 4 divisors (see below), whose sum is σ = 2490100002. Its totient is φ = 830033332.

The previous prime is 1660066631. The next prime is 1660066717. The reversal of 1660066666 is 6666600661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1477249225 + 182817441 = 38435^2 + 13521^2 .

1660066666 is a modest number, since divided by 66666 gives 16600 as remainder.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 415016665 + ... + 415016668.

Almost surely, 2^1660066666 is an apocalyptic number.

1660066666 is a deficient number, since it is larger than the sum of its proper divisors (830033336).

1660066666 is an equidigital number, since it uses as much as digits as its factorization.

1660066666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830033335.

The product of its (nonzero) digits is 279936, while the sum is 43.

The square root of 1660066666 is about 40743.9156930210. The cubic root of 1660066666 is about 1184.0639978837.

The spelling of 1660066666 in words is "one billion, six hundred sixty million, sixty-six thousand, six hundred sixty-six".