685123 has 2 divisors, whose sum is σ = 685124. Its totient is φ = 685122.

The previous prime is 685109. The next prime is 685141. The reversal of 685123 is 321586.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 685123 - 2¹³ = 676931 is a prime.

It is an Ulam number.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (685103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342561 + 342562.

It is an arithmetic number, because the mean of its divisors is an integer number (342562).

2⁶⁸⁵¹²³ is an apocalyptic number.

685123 is a deficient number, since it is larger than the sum of its proper divisors (1).

685123 is an equidigital number, since it uses as much as digits as its factorization.

685123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

The square root of 685123 is about 827.7215715444. The cubic root of 685123 is about 88.1568741062.

It can be divided in two parts, 685 and 123, that multiplied together give a triangular number (84255 = T₄₁₀).

The spelling of 685123 in words is "six hundred eighty-five thousand, one hundred twenty-three".