440000728021 has 2 divisors, whose sum is σ = 440000728022. Its totient is φ = 440000728020.

The previous prime is 440000728019. The next prime is 440000728033. The reversal of 440000728021 is 120827000044.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 388610104996 + 51390623025 = 623386^2 + 226695^2 .

It is a cyclic number.

It is not a de Polignac number, because 440000728021 - 2¹ = 440000728019 is a prime.

It is a super-4 number, since 4×440000728021⁴ (a number of 48 digits) contains 4444 as substring.

Together with 440000728019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (440000728061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 220000364010 + 220000364011.

It is an arithmetic number, because the mean of its divisors is an integer number (220000364011).

Almost surely, 2^440000728021 is an apocalyptic number.

It is an amenable number.

440000728021 is a deficient number, since it is larger than the sum of its proper divisors (1).

440000728021 is an equidigital number, since it uses as much as digits as its factorization.

440000728021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3584, while the sum is 28.

Adding to 440000728021 its reverse (120827000044), we get a palindrome (560827728065).

The spelling of 440000728021 in words is "four hundred forty billion, seven hundred twenty-eight thousand, twenty-one".