667251818161 has 2 divisors, whose sum is σ = 667251818162. Its totient is φ = 667251818160.

The previous prime is 667251818153. The next prime is 667251818171. The reversal of 667251818161 is 161818152766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 580462658161 + 86789160000 = 761881^2 + 294600^2 .

It is a cyclic number.

It is not a de Polignac number, because 667251818161 - 2³ = 667251818153 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 667251818099 and 667251818108.

It is not a weakly prime, because it can be changed into another prime (667251818111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333625909080 + 333625909081.

It is an arithmetic number, because the mean of its divisors is an integer number (333625909081).

Almost surely, 2^667251818161 is an apocalyptic number.

It is an amenable number.

667251818161 is a deficient number, since it is larger than the sum of its proper divisors (1).

667251818161 is an equidigital number, since it uses as much as digits as its factorization.

667251818161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 967680, while the sum is 52.

The spelling of 667251818161 in words is "six hundred sixty-seven billion, two hundred fifty-one million, eight hundred eighteen thousand, one hundred sixty-one".