66656166101 has 4 divisors (see below), whose sum is σ = 76178475552. Its totient is φ = 57133856652.

The previous prime is 66656166097. The next prime is 66656166107. The reversal of 66656166101 is 10166165666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10166165666 = 2 ⋅5083082833.

It is a cyclic number.

It is not a de Polignac number, because 66656166101 - 2² = 66656166097 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66656166107) 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, 4761154715 + ... + 4761154728.

It is an arithmetic number, because the mean of its divisors is an integer number (19044618888).

Almost surely, 2^66656166101 is an apocalyptic number.

It is an amenable number.

66656166101 is a deficient number, since it is larger than the sum of its proper divisors (9522309451).

66656166101 is an equidigital number, since it uses as much as digits as its factorization.

66656166101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9522309450.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 66656166101 in words is "sixty-six billion, six hundred fifty-six million, one hundred sixty-six thousand, one hundred one".