66618243 has 12 divisors (see below), whose sum is σ = 96344248. Its totient is φ = 44357760.

The previous prime is 66618239. The next prime is 66618247. The reversal of 66618243 is 34281666.

66618243 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 an interprime number because it is at equal distance from previous prime (66618239) and next prime (66618247).

It is not a de Polignac number, because 66618243 - 2² = 66618239 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66618198 and 66618207.

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 11 ways as a sum of consecutive naturals, for example, 4083 + ... + 12243.

Almost surely, 2^66618243 is an apocalyptic number.

66618243 is a deficient number, since it is larger than the sum of its proper divisors (29726005).

66618243 is a wasteful number, since it uses less digits than its factorization.

66618243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9074 (or 9071 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 66618243 is about 8161.9999387405. Note that the first 4 decimals coincide. The cubic root of 66618243 is about 405.3819350849.

The spelling of 66618243 in words is "sixty-six million, six hundred eighteen thousand, two hundred forty-three".