665377848181 has 2 divisors, whose sum is σ = 665377848182. Its totient is φ = 665377848180.

The previous prime is 665377848119. The next prime is 665377848209. The reversal of 665377848181 is 181848773566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 660213126225 + 5164721956 = 812535^2 + 71866^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665377848181 is a prime.

It is a super-2 number, since 2×665377848181² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665377848101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332688924090 + 332688924091.

It is an arithmetic number, because the mean of its divisors is an integer number (332688924091).

Almost surely, 2^665377848181 is an apocalyptic number.

It is an amenable number.

665377848181 is a deficient number, since it is larger than the sum of its proper divisors (1).

665377848181 is an equidigital number, since it uses as much as digits as its factorization.

665377848181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54190080, while the sum is 64.

The spelling of 665377848181 in words is "six hundred sixty-five billion, three hundred seventy-seven million, eight hundred forty-eight thousand, one hundred eighty-one".