66121700171 has 4 divisors (see below), whose sum is σ = 66122235312. Its totient is φ = 66121165032.

The previous prime is 66121700153. The next prime is 66121700189. The reversal of 66121700171 is 17100712166.

66121700171 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (66121700153) and next prime (66121700189).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66121700171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66121760171) 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, 22826 + ... + 364368.

It is an arithmetic number, because the mean of its divisors is an integer number (16530558828).

Almost surely, 2^66121700171 is an apocalyptic number.

66121700171 is a deficient number, since it is larger than the sum of its proper divisors (535141).

66121700171 is a wasteful number, since it uses less digits than its factorization.

66121700171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535140.

The product of its (nonzero) digits is 3528, while the sum is 32.

The spelling of 66121700171 in words is "sixty-six billion, one hundred twenty-one million, seven hundred thousand, one hundred seventy-one".