21323441 has 2 divisors, whose sum is σ = 21323442. Its totient is φ = 21323440.

The previous prime is 21323417. The next prime is 21323473. The reversal of 21323441 is 14432312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18447025 + 2876416 = 4295^2 + 1696^2 .

It is a cyclic number.

It is not a de Polignac number, because 21323441 - 2¹⁰ = 21322417 is a prime.

It is not a weakly prime, because it can be changed into another prime (21323641) 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, 10661720 + 10661721.

It is an arithmetic number, because the mean of its divisors is an integer number (10661721).

Almost surely, 2^21323441 is an apocalyptic number.

It is an amenable number.

21323441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323441 is an equidigital number, since it uses as much as digits as its factorization.

21323441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 20.

The square root of 21323441 is about 4617.7311528498. The cubic root of 21323441 is about 277.3016346072.

Adding to 21323441 its reverse (14432312), we get a palindrome (35755753).

The spelling of 21323441 in words is "twenty-one million, three hundred twenty-three thousand, four hundred forty-one".