685586149109 has 2 divisors, whose sum is σ = 685586149110. Its totient is φ = 685586149108.

The previous prime is 685586149091. The next prime is 685586149117. The reversal of 685586149109 is 901941685586.

Together with previous prime (685586149091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 666677149009 + 18909000100 = 816503^2 + 137510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685586149109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685586149169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342793074554 + 342793074555.

It is an arithmetic number, because the mean of its divisors is an integer number (342793074555).

Almost surely, 2^685586149109 is an apocalyptic number.

It is an amenable number.

685586149109 is a deficient number, since it is larger than the sum of its proper divisors (1).

685586149109 is an equidigital number, since it uses as much as digits as its factorization.

685586149109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18662400, while the sum is 62.

The spelling of 685586149109 in words is "six hundred eighty-five billion, five hundred eighty-six million, one hundred forty-nine thousand, one hundred nine".