44640 has 72 divisors (see below), whose sum is σ = 157248. Its totient is φ = 11520.

The previous prime is 44633. The next prime is 44641. The reversal of 44640 is 4644.

Added to its reverse (4644) it gives a square (49284 = 222²).

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a d-powerful number, because it can be written as 4⁶ + 4⁷ + 6⁵ + 4⁷ + 0 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (44641) by changing a digit.

44640 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 (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1425 + ... + 1455.

It is an arithmetic number, because the mean of its divisors is an integer number (2184).

2⁴⁴⁶⁴⁰ is an apocalyptic number.

44640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 44640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78624).

44640 is an abundant number, since it is smaller than the sum of its proper divisors (112608).

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

44640 is a wasteful number, since it uses less digits than its factorization.

44640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 44640 is about 211.2818023399. The cubic root of 44640 is about 35.4738284920.

Adding to 44640 its reverse (4644), we get a square (49284 = 222²).

The spelling of 44640 in words is "forty-four thousand, six hundred forty".