66823843 has 4 divisors (see below), whose sum is σ = 66990888. Its totient is φ = 66656800.

The previous prime is 66823837. The next prime is 66823871. The reversal of 66823843 is 34832866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34832866 = 2 ⋅17416433.

It is a cyclic number.

It is not a de Polignac number, because 66823843 - 2⁵ = 66823811 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66823796 and 66823805.

It is not an unprimeable number, because it can be changed into a prime (66823873) 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, 82921 + ... + 83722.

It is an arithmetic number, because the mean of its divisors is an integer number (16747722).

Almost surely, 2^66823843 is an apocalyptic number.

66823843 is a deficient number, since it is larger than the sum of its proper divisors (167045).

66823843 is a wasteful number, since it uses less digits than its factorization.

66823843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167044.

The product of its digits is 165888, while the sum is 40.

The square root of 66823843 is about 8174.5851882527. The cubic root of 66823843 is about 405.7985423399.

The spelling of 66823843 in words is "sixty-six million, eight hundred twenty-three thousand, eight hundred forty-three".