685191717361 has 2 divisors, whose sum is σ = 685191717362. Its totient is φ = 685191717360.

The previous prime is 685191717347. The next prime is 685191717473. The reversal of 685191717361 is 163717191586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 474114873600 + 211076843761 = 688560^2 + 459431^2 .

It is a cyclic number.

It is not a de Polignac number, because 685191717361 - 2⁷ = 685191717233 is a prime.

It is not a weakly prime, because it can be changed into another prime (685191717061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342595858680 + 342595858681.

It is an arithmetic number, because the mean of its divisors is an integer number (342595858681).

Almost surely, 2^685191717361 is an apocalyptic number.

It is an amenable number.

685191717361 is a deficient number, since it is larger than the sum of its proper divisors (1).

685191717361 is an equidigital number, since it uses as much as digits as its factorization.

685191717361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1905120, while the sum is 55.

The spelling of 685191717361 in words is "six hundred eighty-five billion, one hundred ninety-one million, seven hundred seventeen thousand, three hundred sixty-one".