66563843 has 4 divisors (see below), whose sum is σ = 66622728. Its totient is φ = 66504960.

The previous prime is 66563807. The next prime is 66563867. The reversal of 66563843 is 34836566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34836566 = 2 ⋅17418283.

It is a cyclic number.

It is not a de Polignac number, because 66563843 - 2¹² = 66559747 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 66563843.

It is not an unprimeable number, because it can be changed into a prime (66563873) 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 3 ways as a sum of consecutive naturals, for example, 27713 + ... + 30018.

It is an arithmetic number, because the mean of its divisors is an integer number (16655682).

Almost surely, 2^66563843 is an apocalyptic number.

66563843 is a deficient number, since it is larger than the sum of its proper divisors (58885).

66563843 is a wasteful number, since it uses less digits than its factorization.

66563843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58884.

The product of its digits is 311040, while the sum is 41.

The square root of 66563843 is about 8158.6667415700. Note that the first 3 decimals coincide. The cubic root of 66563843 is about 405.2715610005.

The spelling of 66563843 in words is "sixty-six million, five hundred sixty-three thousand, eight hundred forty-three".