644250 has 32 divisors (see below), whose sum is σ = 1609920. Its totient is φ = 171600.

The previous prime is 644239. The next prime is 644257. The reversal of 644250 is 52446.

It is a happy number.

644250 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 644250.

It is not an unprimeable number, because it can be changed into a prime (644257) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 321 + ... + 1179.

It is an arithmetic number, because the mean of its divisors is an integer number (50310).

2⁶⁴⁴²⁵⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (804960).

644250 is an abundant number, since it is smaller than the sum of its proper divisors (965670).

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

644250 is a wasteful number, since it uses less digits than its factorization.

644250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879 (or 869 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 644250 is about 802.6518547914. The cubic root of 644250 is about 86.3677241413.

Adding to 644250 its reverse (52446), we get a palindrome (696696).

The spelling of 644250 in words is "six hundred forty-four thousand, two hundred fifty".