664144 has 40 divisors (see below), whose sum is σ = 1444352. Its totient is φ = 293760.

The previous prime is 664141. The next prime is 664151. The reversal of 664144 is 441466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664141) 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, 6397 + ... + 6499.

2⁶⁶⁴¹⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (722176).

664144 is an abundant number, since it is smaller than the sum of its proper divisors (780208).

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

664144 is a wasteful number, since it uses less digits than its factorization.

664144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 149 counting only the distinct ones).

The product of its digits is 2304, while the sum is 25.

The square root of 664144 is about 814.9503052334. The cubic root of 664144 is about 87.2477195815.

It can be divided in two parts, 664 and 144, that added together give a palindrome (808).

The spelling of 664144 in words is "six hundred sixty-four thousand, one hundred forty-four".