665182181 has 2 divisors, whose sum is σ = 665182182. Its totient is φ = 665182180.

The previous prime is 665182157. The next prime is 665182187. The reversal of 665182181 is 181281566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 665124100 + 58081 = 25790^2 + 241^2 .

It is a cyclic number.

It is not a de Polignac number, because 665182181 - 2¹⁰ = 665181157 is a prime.

It is a super-2 number, since 2×665182181² = 884934667839833522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665182187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332591090 + 332591091.

It is an arithmetic number, because the mean of its divisors is an integer number (332591091).

Almost surely, 2^665182181 is an apocalyptic number.

It is an amenable number.

665182181 is a deficient number, since it is larger than the sum of its proper divisors (1).

665182181 is an equidigital number, since it uses as much as digits as its factorization.

665182181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 38.

The square root of 665182181 is about 25791.1260126424. The cubic root of 665182181 is about 872.9315740239.

The spelling of 665182181 in words is "six hundred sixty-five million, one hundred eighty-two thousand, one hundred eighty-one".