645641200 has 60 divisors (see below), whose sum is σ = 1572472768. Its totient is φ = 254707200.

The previous prime is 645641179. The next prime is 645641233. The reversal of 645641200 is 2146546.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18145 + ... + 40255.

Almost surely, 2^645641200 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645641200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (786236384).

645641200 is an abundant number, since it is smaller than the sum of its proper divisors (926831568).

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

645641200 is a wasteful number, since it uses less digits than its factorization.

645641200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22202 (or 22191 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 645641200 is about 25409.4706753210. The cubic root of 645641200 is about 864.2984722683.

Adding to 645641200 its reverse (2146546), we get a palindrome (647787746).

The spelling of 645641200 in words is "six hundred forty-five million, six hundred forty-one thousand, two hundred".