66565109 has 8 divisors (see below), whose sum is σ = 73623480. Its totient is φ = 59783616.

The previous prime is 66565097. The next prime is 66565111. The reversal of 66565109 is 90156566.

It can be written as a sum of positive squares in 4 ways, for example, as 1311025 + 65254084 = 1145^2 + 8078^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66565109 - 2¹² = 66561013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66565129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68714 + ... + 69675.

It is an arithmetic number, because the mean of its divisors is an integer number (9202935).

Almost surely, 2^66565109 is an apocalyptic number.

It is an amenable number.

66565109 is a deficient number, since it is larger than the sum of its proper divisors (7058371).

66565109 is a wasteful number, since it uses less digits than its factorization.

66565109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138439.

The product of its (nonzero) digits is 48600, while the sum is 38.

The square root of 66565109 is about 8158.7443274073. The cubic root of 66565109 is about 405.2741303161.

The spelling of 66565109 in words is "sixty-six million, five hundred sixty-five thousand, one hundred nine".