1666116611 has 4 divisors (see below), whose sum is σ = 1666416792. Its totient is φ = 1665816432.

The previous prime is 1666116587. The next prime is 1666116679. The reversal of 1666116611 is 1166116661.

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

It is a cyclic number.

It is not a de Polignac number, because 1666116611 - 2⁶ = 1666116547 is a prime.

It is a super-2 number, since 2×1666116611² = 5551889122900250642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666116691) 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, 141605 + ... + 152918.

It is an arithmetic number, because the mean of its divisors is an integer number (416604198).

Almost surely, 2^1666116611 is an apocalyptic number.

1666116611 is a deficient number, since it is larger than the sum of its proper divisors (300181).

1666116611 is an equidigital number, since it uses as much as digits as its factorization.

1666116611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300180.

The product of its digits is 7776, while the sum is 35.

The square root of 1666116611 is about 40818.0917118868. The cubic root of 1666116611 is about 1185.5006545238.

The spelling of 1666116611 in words is "one billion, six hundred sixty-six million, one hundred sixteen thousand, six hundred eleven".