688185161 has 2 divisors, whose sum is σ = 688185162. Its totient is φ = 688185160.

The previous prime is 688185131. The next prime is 688185181. The reversal of 688185161 is 161581886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 548496400 + 139688761 = 23420^2 + 11819^2 .

It is a cyclic number.

It is not a de Polignac number, because 688185161 - 2¹⁰ = 688184137 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (688185131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344092580 + 344092581.

It is an arithmetic number, because the mean of its divisors is an integer number (344092581).

Almost surely, 2^688185161 is an apocalyptic number.

It is an amenable number.

688185161 is a deficient number, since it is larger than the sum of its proper divisors (1).

688185161 is an equidigital number, since it uses as much as digits as its factorization.

688185161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 92160, while the sum is 44.

The square root of 688185161 is about 26233.2834582330. The cubic root of 688185161 is about 882.8801812737.

The spelling of 688185161 in words is "six hundred eighty-eight million, one hundred eighty-five thousand, one hundred sixty-one".