66656117 has 12 divisors (see below), whose sum is σ = 73819788. Its totient is φ = 60139200.

The previous prime is 66656111. The next prime is 66656131. The reversal of 66656117 is 71165666.

It can be written as a sum of positive squares in 2 ways, for example, as 18783556 + 47872561 = 4334^2 + 6919^2 .

It is a de Polignac number, because none of the positive numbers 2^k-66656117 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 (66656111) 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 in 11 ways as a sum of consecutive naturals, for example, 14567 + ... + 18587.

It is an arithmetic number, because the mean of its divisors is an integer number (6151649).

Almost surely, 2^66656117 is an apocalyptic number.

It is an amenable number.

66656117 is a deficient number, since it is larger than the sum of its proper divisors (7163671).

66656117 is a wasteful number, since it uses less digits than its factorization.

66656117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4180 (or 4169 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 66656117 is about 8164.3197512101. The cubic root of 66656117 is about 405.4587435087.

The spelling of 66656117 in words is "sixty-six million, six hundred fifty-six thousand, one hundred seventeen".