665909108899 has 2 divisors, whose sum is σ = 665909108900. Its totient is φ = 665909108898.

The previous prime is 665909108747. The next prime is 665909108927. The reversal of 665909108899 is 998801909566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665909108899 - 2⁹ = 665909108387 is a prime.

It is not a weakly prime, because it can be changed into another prime (665909106899) by changing a digit.

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, 332954554449 + 332954554450.

It is an arithmetic number, because the mean of its divisors is an integer number (332954554450).

Almost surely, 2^665909108899 is an apocalyptic number.

665909108899 is a deficient number, since it is larger than the sum of its proper divisors (1).

665909108899 is an equidigital number, since it uses as much as digits as its factorization.

665909108899 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 75582720, while the sum is 70.

The spelling of 665909108899 in words is "six hundred sixty-five billion, nine hundred nine million, one hundred eight thousand, eight hundred ninety-nine".