644434 has 16 divisors (see below), whose sum is σ = 1115136. Its totient is φ = 273600.

The previous prime is 644431. The next prime is 644443. The reversal of 644434 is 434446.

It is a happy number.

644434 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 644399 and 644408.

It is not an unprimeable number, because it can be changed into a prime (644431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2554 + ... + 2794.

It is an arithmetic number, because the mean of its divisors is an integer number (69696).

2⁶⁴⁴⁴³⁴ is an apocalyptic number.

644434 is a deficient number, since it is larger than the sum of its proper divisors (470702).

644434 is a wasteful number, since it uses less digits than its factorization.

644434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441.

The product of its digits is 4608, while the sum is 25.

The square root of 644434 is about 802.7664666639. The cubic root of 644434 is about 86.3759456643.

The spelling of 644434 in words is "six hundred forty-four thousand, four hundred thirty-four".