16441721 has 2 divisors, whose sum is σ = 16441722. Its totient is φ = 16441720.

The previous prime is 16441693. The next prime is 16441723. The reversal of 16441721 is 12714461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8934121 + 7507600 = 2989^2 + 2740^2 .

It is an emirp because it is prime and its reverse (12714461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16441721 - 2⁶ = 16441657 is a prime.

It is a super-3 number, since 3×16441721³ (a number of 23 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 16441723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16441723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8220860 + 8220861.

It is an arithmetic number, because the mean of its divisors is an integer number (8220861).

Almost surely, 2^16441721 is an apocalyptic number.

It is an amenable number.

16441721 is a deficient number, since it is larger than the sum of its proper divisors (1).

16441721 is an equidigital number, since it uses as much as digits as its factorization.

16441721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1344, while the sum is 26.

The square root of 16441721 is about 4054.8392076629. The cubic root of 16441721 is about 254.2820816808.

The spelling of 16441721 in words is "sixteen million, four hundred forty-one thousand, seven hundred twenty-one".