644574 has 32 divisors (see below), whose sum is σ = 1497600. Its totient is φ = 181152.

The previous prime is 644569. The next prime is 644593. The reversal of 644574 is 475446.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

644574 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4252 + ... + 4400.

It is an arithmetic number, because the mean of its divisors is an integer number (46800).

2⁶⁴⁴⁵⁷⁴ is an apocalyptic number.

644574 is an abundant number, since it is smaller than the sum of its proper divisors (853026).

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

644574 is a wasteful number, since it uses less digits than its factorization.

644574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264.

The product of its digits is 13440, while the sum is 30.

The square root of 644574 is about 802.8536603890. The cubic root of 644574 is about 86.3822001226.

The spelling of 644574 in words is "six hundred forty-four thousand, five hundred seventy-four".