42644 has 12 divisors (see below), whose sum is σ = 85344. Its totient is φ = 18264.

The previous prime is 42643. The next prime is 42649. The reversal of 42644 is 44624.

42644 is nontrivially palindromic in base 3.

42644 is an admirable number.

It is a hoax number, since the sum of its digits (20) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 734 + ... + 789.

It is an arithmetic number, because the mean of its divisors is an integer number (7112).

2⁴²⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

42644 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42672).

42644 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 9 representation: 42644 = (64442)₉.

42644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534 (or 1532 counting only the distinct ones).

The product of its digits is 768, while the sum is 20.

The square root of 42644 is about 206.5042372447. The cubic root of 42644 is about 34.9370296317.

Subtracting from 42644 its sum of digits (20), we obtain a palindrome (42624).

It can be divided in two parts, 42 and 644, that added together give a palindrome (686).

The spelling of 42644 in words is "forty-two thousand, six hundred forty-four".