21010120110101 has 2 divisors, whose sum is σ = 21010120110102. Its totient is φ = 21010120110100.

The previous prime is 21010120110071. The next prime is 21010120110143. The reversal of 21010120110101 is 10101102101012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20940279363025 + 69840747076 = 4576055^2 + 264274^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010120110101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010120110401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505060055050 + 10505060055051.

It is an arithmetic number, because the mean of its divisors is an integer number (10505060055051).

Almost surely, 2^{21010120110101} is an apocalyptic number.

It is an amenable number.

21010120110101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010120110101 is an equidigital number, since it uses as much as digits as its factorization.

21010120110101 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 11.

Adding to 21010120110101 its reverse (10101102101012), we get a palindrome (31111222211113).

The spelling of 21010120110101 in words is "twenty-one trillion, ten billion, one hundred twenty million, one hundred ten thousand, one hundred one".