685517 has 4 divisors (see below), whose sum is σ = 783456. Its totient is φ = 587580.

The previous prime is 685513. The next prime is 685519. The reversal of 685517 is 715586.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 715586 = 2 ⋅357793.

It is not a de Polignac number, because 685517 - 2² = 685513 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48959 + ... + 48972.

It is an arithmetic number, because the mean of its divisors is an integer number (195864).

2⁶⁸⁵⁵¹⁷ is an apocalyptic number.

It is an amenable number.

685517 is a deficient number, since it is larger than the sum of its proper divisors (97939).

685517 is an equidigital number, since it uses as much as digits as its factorization.

685517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97938.

The product of its digits is 8400, while the sum is 32.

The square root of 685517 is about 827.9595400743. The cubic root of 685517 is about 88.1737699299.

The spelling of 685517 in words is "six hundred eighty-five thousand, five hundred seventeen".