21448613 has 2 divisors, whose sum is σ = 21448614. Its totient is φ = 21448612.

The previous prime is 21448607. The next prime is 21448631. The reversal of 21448613 is 31684412.

Together with next prime (21448631) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20232004 + 1216609 = 4498^2 + 1103^2 .

It is a cyclic number.

It is not a de Polignac number, because 21448613 - 2¹⁰ = 21447589 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21448513) 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, 10724306 + 10724307.

It is an arithmetic number, because the mean of its divisors is an integer number (10724307).

Almost surely, 2^21448613 is an apocalyptic number.

It is an amenable number.

21448613 is a deficient number, since it is larger than the sum of its proper divisors (1).

21448613 is an equidigital number, since it uses as much as digits as its factorization.

21448613 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 29.

The square root of 21448613 is about 4631.2647300710. The cubic root of 21448613 is about 277.8431779461.

The spelling of 21448613 in words is "twenty-one million, four hundred forty-eight thousand, six hundred thirteen".