66388571695 has 16 divisors (see below), whose sum is σ = 80134483968. Its totient is φ = 52799081760.

The previous prime is 66388571663. The next prime is 66388571729. The reversal of 66388571695 is 59617588366.

It is not a de Polignac number, because 66388571695 - 2⁵ = 66388571663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1532422 + ... + 1575148.

It is an arithmetic number, because the mean of its divisors is an integer number (5008405248).

Almost surely, 2^66388571695 is an apocalyptic number.

66388571695 is a deficient number, since it is larger than the sum of its proper divisors (13745912273).

66388571695 is a wasteful number, since it uses less digits than its factorization.

66388571695 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44550.

The product of its digits is 65318400, while the sum is 64.

The spelling of 66388571695 in words is "sixty-six billion, three hundred eighty-eight million, five hundred seventy-one thousand, six hundred ninety-five".