21010101121111 has 2 divisors, whose sum is σ = 21010101121112. Its totient is φ = 21010101121110.

The previous prime is 21010101121099. The next prime is 21010101121151. The reversal of 21010101121111 is 11112110101012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21010101121111 - 2³⁷ = 20872662167639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21010101121091 and 21010101121100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010101121151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505050560555 + 10505050560556.

It is an arithmetic number, because the mean of its divisors is an integer number (10505050560556).

Almost surely, 2^{21010101121111} is an apocalyptic number.

21010101121111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010101121111 is an equidigital number, since it uses as much as digits as its factorization.

21010101121111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21010101121111 its reverse (11112110101012), we get a palindrome (32122211222123).

The spelling of 21010101121111 in words is "twenty-one trillion, ten billion, one hundred one million, one hundred twenty-one thousand, one hundred eleven".