645106 has 32 divisors (see below), whose sum is σ = 1244160. Its totient is φ = 243600.

The previous prime is 645097. The next prime is 645131. The reversal of 645106 is 601546.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a nialpdrome in base 15.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 9051 + ... + 9121.

It is an arithmetic number, because the mean of its divisors is an integer number (38880).

2⁶⁴⁵¹⁰⁶ is an apocalyptic number.

645106 is a deficient number, since it is larger than the sum of its proper divisors (599054).

645106 is a wasteful number, since it uses less digits than its factorization.

645106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150.

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

The square root of 645106 is about 803.1849102168. The cubic root of 645106 is about 86.4059588083.

It can be divided in two parts, 64510 and 6, that added together give a square (64516 = 254²).

The spelling of 645106 in words is "six hundred forty-five thousand, one hundred six".