666711161 has 4 divisors (see below), whose sum is σ = 666785892. Its totient is φ = 666636432.

The previous prime is 666711119. The next prime is 666711217. The reversal of 666711161 is 161117666.

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 can be written as a sum of positive squares in 2 ways, for example, as 439153936 + 227557225 = 20956^2 + 15085^2 .

It is a cyclic number.

It is not a de Polignac number, because 666711161 - 2¹⁰ = 666710137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666719161) 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, 21830 + ... + 42543.

It is an arithmetic number, because the mean of its divisors is an integer number (166696473).

Almost surely, 2^666711161 is an apocalyptic number.

It is an amenable number.

666711161 is a deficient number, since it is larger than the sum of its proper divisors (74731).

666711161 is a wasteful number, since it uses less digits than its factorization.

666711161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74730.

The product of its digits is 9072, while the sum is 35.

The square root of 666711161 is about 25820.7505894000. The cubic root of 666711161 is about 873.5998989941.

The spelling of 666711161 in words is "six hundred sixty-six million, seven hundred eleven thousand, one hundred sixty-one".