644534 has 8 divisors (see below), whose sum is σ = 1054728. Its totient is φ = 292960.

The previous prime is 644531. The next prime is 644549. The reversal of 644534 is 435446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14627 + ... + 14670.

It is an arithmetic number, because the mean of its divisors is an integer number (131841).

2⁶⁴⁴⁵³⁴ is an apocalyptic number.

644534 is a deficient number, since it is larger than the sum of its proper divisors (410194).

644534 is a wasteful number, since it uses less digits than its factorization.

644534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29310.

The product of its digits is 5760, while the sum is 26.

The square root of 644534 is about 802.8287488624. The cubic root of 644534 is about 86.3804132269.

The spelling of 644534 in words is "six hundred forty-four thousand, five hundred thirty-four".