21210011 has 2 divisors, whose sum is σ = 21210012. Its totient is φ = 21210010.

The previous prime is 21209963. The next prime is 21210037. The reversal of 21210011 is 11001212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21210011 - 2¹⁸ = 20947867 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21210041) 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, 10605005 + 10605006.

It is an arithmetic number, because the mean of its divisors is an integer number (10605006).

Almost surely, 2^21210011 is an apocalyptic number.

21210011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210011 is an equidigital number, since it uses as much as digits as its factorization.

21210011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 21210011 is about 4605.4327701097. The cubic root of 21210011 is about 276.8090583298.

Adding to 21210011 its reverse (11001212), we get a palindrome (32211223).

The spelling of 21210011 in words is "twenty-one million, two hundred ten thousand, eleven".