645200 has 30 divisors (see below), whose sum is σ = 1551054. Its totient is φ = 257920.

The previous prime is 645187. The next prime is 645233. The reversal of 645200 is 2546.

645200 = T₁₃₅ + T₁₃₆ + ... + T₁₈₄.

It can be written as a sum of positive squares in 3 ways, for example, as 61504 + 583696 = 248^2 + 764^2 .

It is a congruent number.

It is an unprimeable number.

645200 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 407 + ... + 1206.

2⁶⁴⁵²⁰⁰ is an apocalyptic number.

It is an amenable number.

645200 is an abundant number, since it is smaller than the sum of its proper divisors (905854).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645200 is a wasteful number, since it uses less digits than its factorization.

645200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631 (or 1620 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 645200 is about 803.2434251209. The cubic root of 645200 is about 86.4101554135.

Adding to 645200 its reverse (2546), we get a palindrome (647746).

The spelling of 645200 in words is "six hundred forty-five thousand, two hundred".