643085 has 8 divisors (see below), whose sum is σ = 790776. Its totient is φ = 501760.

The previous prime is 643081. The next prime is 643087. The reversal of 643085 is 580346.

It can be written as a sum of positive squares in 4 ways, for example, as 104329 + 538756 = 323^2 + 734^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643085 - 2² = 643081 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 (643081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1364 + ... + 1773.

It is an arithmetic number, because the mean of its divisors is an integer number (98847).

2⁶⁴³⁰⁸⁵ is an apocalyptic number.

It is an amenable number.

643085 is a deficient number, since it is larger than the sum of its proper divisors (147691).

643085 is a wasteful number, since it uses less digits than its factorization.

643085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3183.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 643085 is about 801.9258070420. The cubic root of 643085 is about 86.3156330228.

The spelling of 643085 in words is "six hundred forty-three thousand, eighty-five".