21010120111 has 2 divisors, whose sum is σ = 21010120112. Its totient is φ = 21010120110.

The previous prime is 21010120069. The next prime is 21010120127. The reversal of 21010120111 is 11102101012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010120111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010120211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505060055 + 10505060056.

It is an arithmetic number, because the mean of its divisors is an integer number (10505060056).

Almost surely, 2^21010120111 is an apocalyptic number.

21010120111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010120111 is an equidigital number, since it uses as much as digits as its factorization.

21010120111 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 10.

Adding to 21010120111 its reverse (11102101012), we get a palindrome (32112221123).

The spelling of 21010120111 in words is "twenty-one billion, ten million, one hundred twenty thousand, one hundred eleven".