21541339 has 2 divisors, whose sum is σ = 21541340. Its totient is φ = 21541338.

The previous prime is 21541337. The next prime is 21541361. The reversal of 21541339 is 93314512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21541339 - 2¹ = 21541337 is a prime.

Together with 21541337, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21541337) 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, 10770669 + 10770670.

It is an arithmetic number, because the mean of its divisors is an integer number (10770670).

Almost surely, 2^21541339 is an apocalyptic number.

21541339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21541339 is an equidigital number, since it uses as much as digits as its factorization.

21541339 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 28.

The square root of 21541339 is about 4641.2648060631. The cubic root of 21541339 is about 278.2429901092.

The spelling of 21541339 in words is "twenty-one million, five hundred forty-one thousand, three hundred thirty-nine".