66243820543 has 4 divisors (see below), whose sum is σ = 66428344080. Its totient is φ = 66059297008.

The previous prime is 66243820529. The next prime is 66243820603. The reversal of 66243820543 is 34502834266.

It is a happy number.

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 66243820543 - 2⁹ = 66243820031 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 66243820543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66243821543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92261230 + ... + 92261947.

It is an arithmetic number, because the mean of its divisors is an integer number (16607086020).

Almost surely, 2^66243820543 is an apocalyptic number.

66243820543 is a deficient number, since it is larger than the sum of its proper divisors (184523537).

66243820543 is a wasteful number, since it uses less digits than its factorization.

66243820543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184523536.

The product of its (nonzero) digits is 829440, while the sum is 43.

The spelling of 66243820543 in words is "sixty-six billion, two hundred forty-three million, eight hundred twenty thousand, five hundred forty-three".