685758857591 has 2 divisors, whose sum is σ = 685758857592. Its totient is φ = 685758857590.

The previous prime is 685758857573. The next prime is 685758857599. The reversal of 685758857591 is 195758857586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685758857591 - 2²² = 685754663287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685758857599) 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, 342879428795 + 342879428796.

It is an arithmetic number, because the mean of its divisors is an integer number (342879428796).

Almost surely, 2^685758857591 is an apocalyptic number.

685758857591 is a deficient number, since it is larger than the sum of its proper divisors (1).

685758857591 is an equidigital number, since it uses as much as digits as its factorization.

685758857591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720000, while the sum is 74.

The spelling of 685758857591 in words is "six hundred eighty-five billion, seven hundred fifty-eight million, eight hundred fifty-seven thousand, five hundred ninety-one".