666088109 has 4 divisors (see below), whose sum is σ = 670950204. Its totient is φ = 661226016.

The previous prime is 666088069. The next prime is 666088117. The reversal of 666088109 is 901880666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 901880666 = 2 ⋅450940333.

It can be written as a sum of positive squares in 2 ways, for example, as 281065225 + 385022884 = 16765^2 + 19622^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666088109 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666088109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666088309) 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, 2430842 + ... + 2431115.

It is an arithmetic number, because the mean of its divisors is an integer number (167737551).

Almost surely, 2^666088109 is an apocalyptic number.

It is an amenable number.

666088109 is a deficient number, since it is larger than the sum of its proper divisors (4862095).

666088109 is a wasteful number, since it uses less digits than its factorization.

666088109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4862094.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 666088109 is about 25808.6828218722. The cubic root of 666088109 is about 873.3276832602.

The spelling of 666088109 in words is "six hundred sixty-six million, eighty-eight thousand, one hundred nine".