21241013 has 2 divisors, whose sum is σ = 21241014. Its totient is φ = 21241012.

The previous prime is 21240991. The next prime is 21241037. The reversal of 21241013 is 31014212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12229009 + 9012004 = 3497^2 + 3002^2 .

It is a cyclic number.

It is not a de Polignac number, because 21241013 - 2¹⁶ = 21175477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21241043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10620506 + 10620507.

It is an arithmetic number, because the mean of its divisors is an integer number (10620507).

Almost surely, 2^21241013 is an apocalyptic number.

It is an amenable number.

21241013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21241013 is an equidigital number, since it uses as much as digits as its factorization.

21241013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21241013 is about 4608.7973485498. The cubic root of 21241013 is about 276.9438603446.

Adding to 21241013 its reverse (31014212), we get a palindrome (52255225).

The spelling of 21241013 in words is "twenty-one million, two hundred forty-one thousand, thirteen".