66511011605 has 8 divisors (see below), whose sum is σ = 79869075000. Its totient is φ = 53171568576.

The previous prime is 66511011569. The next prime is 66511011607. The reversal of 66511011605 is 50611011566.

It can be written as a sum of positive squares in 4 ways, for example, as 4433295889 + 62077715716 = 66583^2 + 249154^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66511011605 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66511011607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4647230 + ... + 4661519.

It is an arithmetic number, because the mean of its divisors is an integer number (9983634375).

Almost surely, 2^66511011605 is an apocalyptic number.

It is an amenable number.

66511011605 is a deficient number, since it is larger than the sum of its proper divisors (13358063395).

66511011605 is a wasteful number, since it uses less digits than its factorization.

66511011605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9310183.

The product of its (nonzero) digits is 5400, while the sum is 32.

The spelling of 66511011605 in words is "sixty-six billion, five hundred eleven million, eleven thousand, six hundred five".