443640221 has 4 divisors (see below), whose sum is σ = 449256000. Its totient is φ = 438024444.

The previous prime is 443640217. The next prime is 443640247. The reversal of 443640221 is 122046344.

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 not a de Polignac number, because 443640221 - 2² = 443640217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (443600221) 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, 2807771 + ... + 2807928.

It is an arithmetic number, because the mean of its divisors is an integer number (112314000).

Almost surely, 2^443640221 is an apocalyptic number.

It is an amenable number.

443640221 is a deficient number, since it is larger than the sum of its proper divisors (5615779).

443640221 is an equidigital number, since it uses as much as digits as its factorization.

443640221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5615778.

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 443640221 is about 21062.7685976939. The cubic root of 443640221 is about 762.6822474341.

Adding to 443640221 its reverse (122046344), we get a palindrome (565686565).

The spelling of 443640221 in words is "four hundred forty-three million, six hundred forty thousand, two hundred twenty-one".