645218 has 16 divisors (see below), whose sum is σ = 1171584. Its totient is φ = 260160.

The previous prime is 645187. The next prime is 645233. The reversal of 645218 is 812546.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1118 + ... + 1593.

It is an arithmetic number, because the mean of its divisors is an integer number (73224).

2⁶⁴⁵²¹⁸ is an apocalyptic number.

645218 is a deficient number, since it is larger than the sum of its proper divisors (526366).

645218 is a wasteful number, since it uses less digits than its factorization.

645218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2737.

The product of its digits is 1920, while the sum is 26.

The square root of 645218 is about 803.2546296163. The cubic root of 645218 is about 86.4109589723.

The spelling of 645218 in words is "six hundred forty-five thousand, two hundred eighteen".