66709335545 has 4 divisors (see below), whose sum is σ = 80051202660. Its totient is φ = 53367468432.

The previous prime is 66709335541. The next prime is 66709335557. The reversal of 66709335545 is 54553390766.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18333972409 + 48375363136 = 135403^2 + 219944^2 .

It is a cyclic number.

It is not a de Polignac number, because 66709335545 - 2² = 66709335541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66709335541) 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, 6670933550 + ... + 6670933559.

It is an arithmetic number, because the mean of its divisors is an integer number (20012800665).

Almost surely, 2^66709335545 is an apocalyptic number.

It is an amenable number.

66709335545 is a deficient number, since it is larger than the sum of its proper divisors (13341867115).

66709335545 is a wasteful number, since it uses less digits than its factorization.

66709335545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13341867114.

The product of its (nonzero) digits is 10206000, while the sum is 53.

The spelling of 66709335545 in words is "sixty-six billion, seven hundred nine million, three hundred thirty-five thousand, five hundred forty-five".