21313241 has 2 divisors, whose sum is σ = 21313242. Its totient is φ = 21313240.

The previous prime is 21313207. The next prime is 21313247. The reversal of 21313241 is 14231312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11703241 + 9610000 = 3421^2 + 3100^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313241 - 2¹⁴ = 21296857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21313247) 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, 10656620 + 10656621.

It is an arithmetic number, because the mean of its divisors is an integer number (10656621).

Almost surely, 2^21313241 is an apocalyptic number.

It is an amenable number.

21313241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21313241 is an equidigital number, since it uses as much as digits as its factorization.

21313241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 17.

The square root of 21313241 is about 4616.6265822568. The cubic root of 21313241 is about 277.2574121043.

Adding to 21313241 its reverse (14231312), we get a palindrome (35544553).

The spelling of 21313241 in words is "twenty-one million, three hundred thirteen thousand, two hundred forty-one".