660778339181 has 2 divisors, whose sum is σ = 660778339182. Its totient is φ = 660778339180.

The previous prime is 660778339103. The next prime is 660778339189. The reversal of 660778339181 is 181933877066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 557499662281 + 103278676900 = 746659^2 + 321370^2 .

It is a cyclic number.

It is not a de Polignac number, because 660778339181 - 2³⁸ = 385900432237 is a prime.

It is a super-2 number, since 2×660778339181² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 660778339181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660778339189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330389169590 + 330389169591.

It is an arithmetic number, because the mean of its divisors is an integer number (330389169591).

Almost surely, 2^660778339181 is an apocalyptic number.

It is an amenable number.

660778339181 is a deficient number, since it is larger than the sum of its proper divisors (1).

660778339181 is an equidigital number, since it uses as much as digits as its factorization.

660778339181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9144576, while the sum is 59.

The spelling of 660778339181 in words is "six hundred sixty billion, seven hundred seventy-eight million, three hundred thirty-nine thousand, one hundred eighty-one".