644450 has 12 divisors (see below), whose sum is σ = 1198770. Its totient is φ = 257760.

The previous prime is 644447. The next prime is 644489. The reversal of 644450 is 54446.

Added to its reverse (54446) it gives a square (698896 = 836²).

It is a happy number.

644450 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 519841 + 124609 = 721^2 + 353^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 644450.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6395 + ... + 6494.

2⁶⁴⁴⁴⁵⁰ is an apocalyptic number.

644450 is a deficient number, since it is larger than the sum of its proper divisors (554320).

644450 is a wasteful number, since it uses less digits than its factorization.

644450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12901 (or 12896 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 644450 is about 802.7764321404. The cubic root of 644450 is about 86.3766605054.

Adding to 644450 its reverse (54446), we get a palindrome (698896).

The spelling of 644450 in words is "six hundred forty-four thousand, four hundred fifty".