685497161 has 2 divisors, whose sum is σ = 685497162. Its totient is φ = 685497160.

The previous prime is 685497107. The next prime is 685497179. The reversal of 685497161 is 161794586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 574321225 + 111175936 = 23965^2 + 10544^2 .

It is a cyclic number.

It is not a de Polignac number, because 685497161 - 2¹⁰ = 685496137 is a prime.

It is not a weakly prime, because it can be changed into another prime (685497101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342748580 + 342748581.

It is an arithmetic number, because the mean of its divisors is an integer number (342748581).

Almost surely, 2^685497161 is an apocalyptic number.

It is an amenable number.

685497161 is a deficient number, since it is larger than the sum of its proper divisors (1).

685497161 is an equidigital number, since it uses as much as digits as its factorization.

685497161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 47.

The square root of 685497161 is about 26182.0007065923. Note that the first 3 decimals coincide. The cubic root of 685497161 is about 881.7291933283.

The spelling of 685497161 in words is "six hundred eighty-five million, four hundred ninety-seven thousand, one hundred sixty-one".