685553 has 4 divisors (see below), whose sum is σ = 747888. Its totient is φ = 623220.

The previous prime is 685547. The next prime is 685591. The reversal of 685553 is 355586.

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.

It is a cyclic number.

It is not a de Polignac number, because 685553 - 2⁴ = 685537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (685513) 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, 31151 + ... + 31172.

It is an arithmetic number, because the mean of its divisors is an integer number (186972).

2⁶⁸⁵⁵⁵³ is an apocalyptic number.

It is an amenable number.

685553 is a deficient number, since it is larger than the sum of its proper divisors (62335).

685553 is a wasteful number, since it uses less digits than its factorization.

685553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62334.

The product of its digits is 18000, while the sum is 32.

The square root of 685553 is about 827.9812799816. The cubic root of 685553 is about 88.1753133879.

The spelling of 685553 in words is "six hundred eighty-five thousand, five hundred fifty-three".