• 440 can be written using four 4's:
440 has 16 divisors (see below), whose sum is σ = 1080. Its totient is φ = 160.
The previous prime is 439. The next prime is 443. The reversal of 440 is 44.
Added to its reverse (44) it gives a square (484 = 222).
It is a happy number.
It is a Cunningham number, because it is equal to 212-1.
440 is a Gilda number.
It is a Harshad number since it is a multiple of its sum of digits (8).
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a plaindrome in base 7, base 13 and base 14.
It is a nialpdrome in base 10.
It is a zygodrome in base 7.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (443) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (5) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35 + ... + 45.
440 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 440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (540).
440 is an abundant number, since it is smaller than the sum of its proper divisors (640).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
440 is a wasteful number, since it uses less digits than its factorization.
440 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 22 (or 18 counting only the distinct ones).
The product of its (nonzero) digits is 16, while the sum is 8.
The square root of 440 is about 20.9761769634. The cubic root of 440 is about 7.6059049215.
Subtracting from 440 its product of nonzero digits (16), we obtain a palindrome (424).
Adding to 440 its reverse (44), we get a palindrome (484).
It can be divided in two parts, 4 and 40, that added together give a palindrome (44).
The spelling of 440 in words is "four hundred forty", and thus it is an aban number and an iban number.
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