66243535439 has 4 divisors (see below), whose sum is σ = 66479277840. Its totient is φ = 66007793040.

The previous prime is 66243535387. The next prime is 66243535507. The reversal of 66243535439 is 93453534266.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66243535439 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 (66243535339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117870779 + ... + 117871340.

It is an arithmetic number, because the mean of its divisors is an integer number (16619819460).

Almost surely, 2^66243535439 is an apocalyptic number.

66243535439 is a deficient number, since it is larger than the sum of its proper divisors (235742401).

66243535439 is a wasteful number, since it uses less digits than its factorization.

66243535439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235742400.

The product of its digits is 6998400, while the sum is 50.

The spelling of 66243535439 in words is "sixty-six billion, two hundred forty-three million, five hundred thirty-five thousand, four hundred thirty-nine".