685719017 has 2 divisors, whose sum is σ = 685719018. Its totient is φ = 685719016.

The previous prime is 685718989. The next prime is 685719029. The reversal of 685719017 is 710917586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 683770201 + 1948816 = 26149^2 + 1396^2 .

It is a cyclic number.

It is not a de Polignac number, because 685719017 - 2¹⁰ = 685717993 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (685719037) 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, 342859508 + 342859509.

It is an arithmetic number, because the mean of its divisors is an integer number (342859509).

Almost surely, 2^685719017 is an apocalyptic number.

It is an amenable number.

685719017 is a deficient number, since it is larger than the sum of its proper divisors (1).

685719017 is an equidigital number, since it uses as much as digits as its factorization.

685719017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 105840, while the sum is 44.

The square root of 685719017 is about 26186.2371676421. The cubic root of 685719017 is about 881.8243047421.

The spelling of 685719017 in words is "six hundred eighty-five million, seven hundred nineteen thousand, seventeen".