685218043 has 2 divisors, whose sum is σ = 685218044. Its totient is φ = 685218042.

The previous prime is 685218041. The next prime is 685218067. The reversal of 685218043 is 340812586.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 685218043 - 2¹ = 685218041 is a prime.

Together with 685218041, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 685217993 and 685218011.

It is not a weakly prime, because it can be changed into another prime (685218041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342609021 + 342609022.

It is an arithmetic number, because the mean of its divisors is an integer number (342609022).

Almost surely, 2^685218043 is an apocalyptic number.

685218043 is a deficient number, since it is larger than the sum of its proper divisors (1).

685218043 is an equidigital number, since it uses as much as digits as its factorization.

685218043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 685218043 is about 26176.6698225729. The cubic root of 685218043 is about 881.6095040899.

The spelling of 685218043 in words is "six hundred eighty-five million, two hundred eighteen thousand, forty-three".