21200121011011 has 2 divisors, whose sum is σ = 21200121011012. Its totient is φ = 21200121011010.

The previous prime is 21200121010987. The next prime is 21200121011023. The reversal of 21200121011011 is 11011012100212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21200121011011 - 2⁷ = 21200121010883 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21200121010982 and 21200121011000.

It is not a weakly prime, because it can be changed into another prime (21200121711011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600060505505 + 10600060505506.

It is an arithmetic number, because the mean of its divisors is an integer number (10600060505506).

Almost surely, 2^{21200121011011} is an apocalyptic number.

21200121011011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200121011011 is an equidigital number, since it uses as much as digits as its factorization.

21200121011011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21200121011011 its reverse (11011012100212), we get a palindrome (32211133111223).

The spelling of 21200121011011 in words is "twenty-one trillion, two hundred billion, one hundred twenty-one million, eleven thousand, eleven".