66618245 has 4 divisors (see below), whose sum is σ = 79941900. Its totient is φ = 53294592.

The previous prime is 66618239. The next prime is 66618247. The reversal of 66618245 is 54281666.

66618245 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 8162²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54281666 = 2 ⋅27140833.

It can be written as a sum of positive squares in 2 ways, for example, as 23990404 + 42627841 = 4898^2 + 6529^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66618245 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66618199 and 66618208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66618247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6661820 + ... + 6661829.

It is an arithmetic number, because the mean of its divisors is an integer number (19985475).

Almost surely, 2^66618245 is an apocalyptic number.

It is an amenable number.

66618245 is a deficient number, since it is larger than the sum of its proper divisors (13323655).

66618245 is a wasteful number, since it uses less digits than its factorization.

66618245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13323654.

The product of its digits is 69120, while the sum is 38.

The square root of 66618245 is about 8162.0000612595. Note that the first 4 decimals coincide. The cubic root of 66618245 is about 405.3819391416.

The spelling of 66618245 in words is "sixty-six million, six hundred eighteen thousand, two hundred forty-five".