646105 has 4 divisors (see below), whose sum is σ = 775332. Its totient is φ = 516880.

The previous prime is 646103. The next prime is 646147. The reversal of 646105 is 501646.

646105 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 205209 + 440896 = 453^2 + 664^2 .

It is not a de Polignac number, because 646105 - 2¹ = 646103 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64606 + ... + 64615.

It is an arithmetic number, because the mean of its divisors is an integer number (193833).

2⁶⁴⁶¹⁰⁵ is an apocalyptic number.

It is an amenable number.

646105 is a deficient number, since it is larger than the sum of its proper divisors (129227).

646105 is a wasteful number, since it uses less digits than its factorization.

646105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129226.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 646105 is about 803.8065687714. The cubic root of 646105 is about 86.4505380627.

The spelling of 646105 in words is "six hundred forty-six thousand, one hundred five".