646106 has 4 divisors (see below), whose sum is σ = 969162. Its totient is φ = 323052.

The previous prime is 646103. The next prime is 646147. The reversal of 646106 is 601646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 601646 = 2 ⋅300823.

It can be written as a sum of positive squares in only one way, i.e., 410881 + 235225 = 641^2 + 485^2 .

It is an Ulam 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 as a sum of consecutive naturals, namely, 161525 + ... + 161528.

2⁶⁴⁶¹⁰⁶ is an apocalyptic number.

646106 is a deficient number, since it is larger than the sum of its proper divisors (323056).

646106 is a wasteful number, since it uses less digits than its factorization.

646106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323055.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 646106 is about 803.8071908113. The cubic root of 646106 is about 86.4505826635.

The spelling of 646106 in words is "six hundred forty-six thousand, one hundred six".