21121220011 has 2 divisors, whose sum is σ = 21121220012. Its totient is φ = 21121220010.

The previous prime is 21121219939. The next prime is 21121220017. The reversal of 21121220011 is 11002212112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21121220011 - 2¹⁷ = 21121088939 is a prime.

It is a super-2 number, since 2×21121220011² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121219973 and 21121220000.

It is not a weakly prime, because it can be changed into another prime (21121220017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560610005 + 10560610006.

It is an arithmetic number, because the mean of its divisors is an integer number (10560610006).

Almost surely, 2^21121220011 is an apocalyptic number.

21121220011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121220011 is an equidigital number, since it uses as much as digits as its factorization.

21121220011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21121220011 its reverse (11002212112), we get a palindrome (32123432123).

The spelling of 21121220011 in words is "twenty-one billion, one hundred twenty-one million, two hundred twenty thousand, eleven".