685539 has 18 divisors (see below), whose sum is σ = 1050036. Its totient is φ = 430920.

The previous prime is 685537. The next prime is 685541. The reversal of 685539 is 935586.

It is an interprime number because it is at equal distance from previous prime (685537) and next prime (685541).

It is not a de Polignac number, because 685539 - 2¹ = 685537 is a prime.

685539 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (685537) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3144 + ... + 3354.

2⁶⁸⁵⁵³⁹ is an apocalyptic number.

685539 is a deficient number, since it is larger than the sum of its proper divisors (364497).

685539 is a wasteful number, since it uses less digits than its factorization.

685539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255 (or 233 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 685539 is about 827.9728256410. The cubic root of 685539 is about 88.1747131607.

Subtracting 685539 from its reverse (935586), we obtain a cube (250047 = 63³).

The spelling of 685539 in words is "six hundred eighty-five thousand, five hundred thirty-nine".