685537 has 2 divisors, whose sum is σ = 685538. Its totient is φ = 685536.

The previous prime is 685519. The next prime is 685541. The reversal of 685537 is 735586.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 678976 + 6561 = 824^2 + 81^2 .

It is a cyclic number.

It is not a de Polignac number, because 685537 - 2¹¹ = 683489 is a prime.

It is not a weakly prime, because it can be changed into another prime (685547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342768 + 342769.

It is an arithmetic number, because the mean of its divisors is an integer number (342769).

2⁶⁸⁵⁵³⁷ is an apocalyptic number.

It is an amenable number.

685537 is a deficient number, since it is larger than the sum of its proper divisors (1).

685537 is an equidigital number, since it uses as much as digits as its factorization.

685537 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25200, while the sum is 34.

The square root of 685537 is about 827.9716178710. The cubic root of 685537 is about 88.1746274133.

The spelling of 685537 in words is "six hundred eighty-five thousand, five hundred thirty-seven".