21441001 has 2 divisors, whose sum is σ = 21441002. Its totient is φ = 21441000.

The previous prime is 21440999. The next prime is 21441011. The reversal of 21441001 is 10014412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16040025 + 5400976 = 4005^2 + 2324^2 .

It is a cyclic number.

It is not a de Polignac number, because 21441001 - 2¹ = 21440999 is a prime.

Together with 21440999, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21441011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10720500 + 10720501.

It is an arithmetic number, because the mean of its divisors is an integer number (10720501).

Almost surely, 2^21441001 is an apocalyptic number.

It is an amenable number.

21441001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21441001 is an equidigital number, since it uses as much as digits as its factorization.

21441001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21441001 is about 4630.4428513912. The cubic root of 21441001 is about 277.8103056960.

Adding to 21441001 its reverse (10014412), we get a palindrome (31455413).

The spelling of 21441001 in words is "twenty-one million, four hundred forty-one thousand, one".