66601616109 has 32 divisors (see below), whose sum is σ = 104155392000. Its totient is φ = 37069700544.

The previous prime is 66601616093. The next prime is 66601616111. The reversal of 66601616109 is 90161610666.

It is not a de Polignac number, because 66601616109 - 2⁴ = 66601616093 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66601616149) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111529 + ... + 381630.

It is an arithmetic number, because the mean of its divisors is an integer number (3254856000).

Almost surely, 2^66601616109 is an apocalyptic number.

It is an amenable number.

66601616109 is a deficient number, since it is larger than the sum of its proper divisors (37553775891).

66601616109 is a wasteful number, since it uses less digits than its factorization.

66601616109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493337.

The product of its (nonzero) digits is 69984, while the sum is 42.

The spelling of 66601616109 in words is "sixty-six billion, six hundred one million, six hundred sixteen thousand, one hundred nine".