168501689 has 2 divisors, whose sum is σ = 168501690. Its totient is φ = 168501688.

The previous prime is 168501661. The next prime is 168501691. The reversal of 168501689 is 986105861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118091689 + 50410000 = 10867^2 + 7100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168501689 is a prime.

It is a Sophie Germain prime.

Together with 168501691, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (168501659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84250844 + 84250845.

It is an arithmetic number, because the mean of its divisors is an integer number (84250845).

Almost surely, 2^168501689 is an apocalyptic number.

It is an amenable number.

168501689 is a deficient number, since it is larger than the sum of its proper divisors (1).

168501689 is an equidigital number, since it uses as much as digits as its factorization.

168501689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 168501689 is about 12980.8200434333. The cubic root of 168501689 is about 552.3335441719. Note that the first 3 decimals are identical.

The spelling of 168501689 in words is "one hundred sixty-eight million, five hundred one thousand, six hundred eighty-nine".