166651509389 has 2 divisors, whose sum is σ = 166651509390. Its totient is φ = 166651509388.

The previous prime is 166651509373. The next prime is 166651509391. The reversal of 166651509389 is 983905156661.

166651509389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89950206889 + 76701302500 = 299917^2 + 276950^2 .

It is a cyclic number.

It is not a de Polignac number, because 166651509389 - 2⁴ = 166651509373 is a prime.

It is a Sophie Germain prime.

Together with 166651509391, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166651589389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83325754694 + 83325754695.

It is an arithmetic number, because the mean of its divisors is an integer number (83325754695).

Almost surely, 2^166651509389 is an apocalyptic number.

It is an amenable number.

166651509389 is a deficient number, since it is larger than the sum of its proper divisors (1).

166651509389 is an equidigital number, since it uses as much as digits as its factorization.

166651509389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10497600, while the sum is 59.

The spelling of 166651509389 in words is "one hundred sixty-six billion, six hundred fifty-one million, five hundred nine thousand, three hundred eighty-nine".