645450 has 48 divisors (see below), whose sum is σ = 1729056. Its totient is φ = 158400.

The previous prime is 645443. The next prime is 645467. The reversal of 645450 is 54546.

645450 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 645450.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1785 + ... + 2115.

It is an arithmetic number, because the mean of its divisors is an integer number (36022).

2⁶⁴⁵⁴⁵⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (864528).

645450 is an abundant number, since it is smaller than the sum of its proper divisors (1083606).

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

645450 is a wasteful number, since it uses less digits than its factorization.

645450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 645450 is about 803.3990291256. The cubic root of 645450 is about 86.4213146144.

Adding to 645450 its reverse (54546), we get a palindrome (699996).

The spelling of 645450 in words is "six hundred forty-five thousand, four hundred fifty".