66802640423 has 4 divisors (see below), whose sum is σ = 67094355240. Its totient is φ = 66510925608.

The previous prime is 66802640407. The next prime is 66802640431. The reversal of 66802640423 is 32404620866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66802640423 - 2⁴ = 66802640407 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 (66802640123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145857065 + ... + 145857522.

It is an arithmetic number, because the mean of its divisors is an integer number (16773588810).

Almost surely, 2^66802640423 is an apocalyptic number.

66802640423 is a deficient number, since it is larger than the sum of its proper divisors (291714817).

66802640423 is a wasteful number, since it uses less digits than its factorization.

66802640423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291714816.

The product of its (nonzero) digits is 331776, while the sum is 41.

The spelling of 66802640423 in words is "sixty-six billion, eight hundred two million, six hundred forty thousand, four hundred twenty-three".