21309341 has 2 divisors, whose sum is σ = 21309342. Its totient is φ = 21309340.

The previous prime is 21309331. The next prime is 21309383. The reversal of 21309341 is 14390312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20702500 + 606841 = 4550^2 + 779^2 .

It is a cyclic number.

It is not a de Polignac number, because 21309341 - 2¹⁸ = 21047197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21309331) 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, 10654670 + 10654671.

It is an arithmetic number, because the mean of its divisors is an integer number (10654671).

Almost surely, 2^21309341 is an apocalyptic number.

It is an amenable number.

21309341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21309341 is an equidigital number, since it uses as much as digits as its factorization.

21309341 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21309341 is about 4616.2041765936. The cubic root of 21309341 is about 277.2404997716.

Adding to 21309341 its reverse (14390312), we get a palindrome (35699653).

The spelling of 21309341 in words is "twenty-one million, three hundred nine thousand, three hundred forty-one".