16661116609 has 2 divisors, whose sum is σ = 16661116610. Its totient is φ = 16661116608.

The previous prime is 16661116601. The next prime is 16661116639. The reversal of 16661116609 is 90661116661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9726890625 + 6934225984 = 98625^2 + 83272^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661116609 - 2³ = 16661116601 is a prime.

It is not a weakly prime, because it can be changed into another prime (16661116601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330558304 + 8330558305.

It is an arithmetic number, because the mean of its divisors is an integer number (8330558305).

Almost surely, 2^16661116609 is an apocalyptic number.

It is an amenable number.

16661116609 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661116609 is an equidigital number, since it uses as much as digits as its factorization.

16661116609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 43.

The spelling of 16661116609 in words is "sixteen billion, six hundred sixty-one million, one hundred sixteen thousand, six hundred nine".