685541 has 2 divisors, whose sum is σ = 685542. Its totient is φ = 685540.

The previous prime is 685537. The next prime is 685547. The reversal of 685541 is 145586.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 664225 + 21316 = 815^2 + 146^2 .

It is a cyclic number.

It is not a de Polignac number, because 685541 - 2² = 685537 is a prime.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 685541.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342770 + 342771.

It is an arithmetic number, because the mean of its divisors is an integer number (342771).

2⁶⁸⁵⁵⁴¹ is an apocalyptic number.

It is an amenable number.

685541 is a deficient number, since it is larger than the sum of its proper divisors (1).

685541 is an equidigital number, since it uses as much as digits as its factorization.

685541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4800, while the sum is 29.

The square root of 685541 is about 827.9740334093. The cubic root of 685541 is about 88.1747989079.

The spelling of 685541 in words is "six hundred eighty-five thousand, five hundred forty-one".