21010101200161 has 2 divisors, whose sum is σ = 21010101200162. Its totient is φ = 21010101200160.

The previous prime is 21010101200017. The next prime is 21010101200273. The reversal of 21010101200161 is 16100210101012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20934797607936 + 75303592225 = 4575456^2 + 274415^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010101200161 - 2¹⁹ = 21010100675873 is a prime.

It is not a weakly prime, because it can be changed into another prime (21010101200761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505050600080 + 10505050600081.

It is an arithmetic number, because the mean of its divisors is an integer number (10505050600081).

Almost surely, 2^{21010101200161} is an apocalyptic number.

It is an amenable number.

21010101200161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010101200161 is an equidigital number, since it uses as much as digits as its factorization.

21010101200161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21010101200161 its reverse (16100210101012), we get a palindrome (37110311301173).

The spelling of 21010101200161 in words is "twenty-one trillion, ten billion, one hundred one million, two hundred thousand, one hundred sixty-one".