440021 has 4 divisors (see below), whose sum is σ = 463200. Its totient is φ = 416844.

The previous prime is 440009. The next prime is 440023. The reversal of 440021 is 120044.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-440021 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 439984 and 440011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (440023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11561 + ... + 11598.

It is an arithmetic number, because the mean of its divisors is an integer number (115800).

2⁴⁴⁰⁰²¹ is an apocalyptic number.

It is an amenable number.

440021 is a deficient number, since it is larger than the sum of its proper divisors (23179).

440021 is a wasteful number, since it uses less digits than its factorization.

440021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23178.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 440021 is about 663.3407872278. The cubic root of 440021 is about 76.0602592263.

Adding to 440021 its reverse (120044), we get a palindrome (560065).

The spelling of 440021 in words is "four hundred forty thousand, twenty-one", and thus it is an iban number.