440721 has 10 divisors (see below), whose sum is σ = 658482. Its totient is φ = 293760.

The previous prime is 440717. The next prime is 440723. The reversal of 440721 is 127044.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 408321 + 32400 = 639^2 + 180^2 .

It is not a de Polignac number, because 440721 - 2² = 440717 is a prime.

440721 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 440694 and 440703.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 440721.

It is not an unprimeable number, because it can be changed into a prime (440723) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2640 + ... + 2801.

2⁴⁴⁰⁷²¹ is an apocalyptic number.

It is an amenable number.

440721 is a deficient number, since it is larger than the sum of its proper divisors (217761).

440721 is an equidigital number, since it uses as much as digits as its factorization.

440721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5453 (or 5444 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 440721 is about 663.8682098128. The cubic root of 440721 is about 76.1005709184.

Adding to 440721 its reverse (127044), we get a palindrome (567765).

The spelling of 440721 in words is "four hundred forty thousand, seven hundred twenty-one", and thus it is an iban number.