1666566667 has 4 divisors (see below), whose sum is σ = 1670918400. Its totient is φ = 1662214936.

The previous prime is 1666566653. The next prime is 1666566701. The reversal of 1666566667 is 7666656661.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666566667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666566767) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2175292 + ... + 2176057.

It is an arithmetic number, because the mean of its divisors is an integer number (417729600).

Almost surely, 2^1666566667 is an apocalyptic number.

1666566667 is a deficient number, since it is larger than the sum of its proper divisors (4351733).

1666566667 is an equidigital number, since it uses as much as digits as its factorization.

1666566667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4351732.

The product of its digits is 9797760, while the sum is 55.

The square root of 1666566667 is about 40823.6042872258. The cubic root of 1666566667 is about 1185.6073884794.

The spelling of 1666566667 in words is "one billion, six hundred sixty-six million, five hundred sixty-six thousand, six hundred sixty-seven".