667171889 has 2 divisors, whose sum is σ = 667171890. Its totient is φ = 667171888.

The previous prime is 667171867. The next prime is 667171913. The reversal of 667171889 is 988171766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 442681600 + 224490289 = 21040^2 + 14983^2 .

It is a cyclic number.

It is not a de Polignac number, because 667171889 - 2⁸ = 667171633 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 667171889.

It is not a weakly prime, because it can be changed into another prime (667171819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333585944 + 333585945.

It is an arithmetic number, because the mean of its divisors is an integer number (333585945).

Almost surely, 2^667171889 is an apocalyptic number.

It is an amenable number.

667171889 is a deficient number, since it is larger than the sum of its proper divisors (1).

667171889 is an equidigital number, since it uses as much as digits as its factorization.

667171889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 53.

The square root of 667171889 is about 25829.6707102510. The cubic root of 667171889 is about 873.8010851949.

The spelling of 667171889 in words is "six hundred sixty-seven million, one hundred seventy-one thousand, eight hundred eighty-nine".