66833942779 has 4 divisors (see below), whose sum is σ = 66865574776. Its totient is φ = 66802310784.

The previous prime is 66833942761. The next prime is 66833942911. The reversal of 66833942779 is 97724933866.

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 66833942779 - 2⁹ = 66833942267 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 66833942779.

It is not an unprimeable number, because it can be changed into a prime (66833942719) 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, 15812829 + ... + 15817054.

It is an arithmetic number, because the mean of its divisors is an integer number (16716393694).

Almost surely, 2^66833942779 is an apocalyptic number.

66833942779 is a deficient number, since it is larger than the sum of its proper divisors (31631997).

66833942779 is a wasteful number, since it uses less digits than its factorization.

66833942779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31631996.

The product of its digits is 82301184, while the sum is 64.

The spelling of 66833942779 in words is "sixty-six billion, eight hundred thirty-three million, nine hundred forty-two thousand, seven hundred seventy-nine".