21234321011 has 2 divisors, whose sum is σ = 21234321012. Its totient is φ = 21234321010.

The previous prime is 21234320999. The next prime is 21234321013. The reversal of 21234321011 is 11012343212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21234321011 is a prime.

It is a Sophie Germain prime.

Together with 21234321013, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21234321013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617160505 + 10617160506.

It is an arithmetic number, because the mean of its divisors is an integer number (10617160506).

Almost surely, 2^21234321011 is an apocalyptic number.

21234321011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234321011 is an equidigital number, since it uses as much as digits as its factorization.

21234321011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21234321011 its reverse (11012343212), we get a palindrome (32246664223).

The spelling of 21234321011 in words is "twenty-one billion, two hundred thirty-four million, three hundred twenty-one thousand, eleven".