201668689 has 2 divisors, whose sum is σ = 201668690. Its totient is φ = 201668688.

The previous prime is 201668651. The next prime is 201668693. The reversal of 201668689 is 986866102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169859089 + 31809600 = 13033^2 + 5640^2 .

It is a cyclic number.

It is not a de Polignac number, because 201668689 - 2⁷ = 201668561 is a prime.

It is not a weakly prime, because it can be changed into another prime (201668189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100834344 + 100834345.

It is an arithmetic number, because the mean of its divisors is an integer number (100834345).

Almost surely, 2^201668689 is an apocalyptic number.

It is an amenable number.

201668689 is a deficient number, since it is larger than the sum of its proper divisors (1).

201668689 is an equidigital number, since it uses as much as digits as its factorization.

201668689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 46.

The square root of 201668689 is about 14201.0101401274. The cubic root of 201668689 is about 586.4254705749.

The spelling of 201668689 in words is "two hundred one million, six hundred sixty-eight thousand, six hundred eighty-nine".