21211339 has 2 divisors, whose sum is σ = 21211340. Its totient is φ = 21211338.

The previous prime is 21211319. The next prime is 21211363. The reversal of 21211339 is 93311212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21211339 - 2¹⁵ = 21178571 is a prime.

It is not a weakly prime, because it can be changed into another prime (21211319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605669 + 10605670.

It is an arithmetic number, because the mean of its divisors is an integer number (10605670).

Almost surely, 2^21211339 is an apocalyptic number.

21211339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211339 is an equidigital number, since it uses as much as digits as its factorization.

21211339 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 22.

The square root of 21211339 is about 4605.5769454000. The cubic root of 21211339 is about 276.8148353936.

The spelling of 21211339 in words is "twenty-one million, two hundred eleven thousand, three hundred thirty-nine".