685637 has 2 divisors, whose sum is σ = 685638. Its totient is φ = 685636.

The previous prime is 685631. The next prime is 685649. The reversal of 685637 is 736586.

It is a happy number.

685637 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 454276 + 231361 = 674^2 + 481^2 .

It is a cyclic number.

It is not a de Polignac number, because 685637 - 2⁴ = 685621 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 685597 and 685606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342818 + 342819.

It is an arithmetic number, because the mean of its divisors is an integer number (342819).

2⁶⁸⁵⁶³⁷ is an apocalyptic number.

It is an amenable number.

685637 is a deficient number, since it is larger than the sum of its proper divisors (1).

685637 is an equidigital number, since it uses as much as digits as its factorization.

685637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 35.

The square root of 685637 is about 828.0320042124. The cubic root of 685637 is about 88.1789145799.

The spelling of 685637 in words is "six hundred eighty-five thousand, six hundred thirty-seven".