21120110161 has 2 divisors, whose sum is σ = 21120110162. Its totient is φ = 21120110160.

The previous prime is 21120110153. The next prime is 21120110177. The reversal of 21120110161 is 16101102112.

It is an a-pointer prime, because the next prime (21120110177) can be obtained adding 21120110161 to its sum of digits (16).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20659750225 + 460359936 = 143735^2 + 21456^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120110161 - 2³ = 21120110153 is a prime.

It is not a weakly prime, because it can be changed into another prime (21120110461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560055080 + 10560055081.

It is an arithmetic number, because the mean of its divisors is an integer number (10560055081).

Almost surely, 2^21120110161 is an apocalyptic number.

It is an amenable number.

21120110161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120110161 is an equidigital number, since it uses as much as digits as its factorization.

21120110161 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 21120110161 its reverse (16101102112), we get a palindrome (37221212273).

The spelling of 21120110161 in words is "twenty-one billion, one hundred twenty million, one hundred ten thousand, one hundred sixty-one".