21112110961 has 2 divisors, whose sum is σ = 21112110962. Its totient is φ = 21112110960.

The previous prime is 21112110959. The next prime is 21112111019. The reversal of 21112110961 is 16901121112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17385741025 + 3726369936 = 131855^2 + 61044^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112110961 - 2¹ = 21112110959 is a prime.

Together with 21112110959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21112110931) 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, 10556055480 + 10556055481.

It is an arithmetic number, because the mean of its divisors is an integer number (10556055481).

Almost surely, 2^21112110961 is an apocalyptic number.

It is an amenable number.

21112110961 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112110961 is an equidigital number, since it uses as much as digits as its factorization.

21112110961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 25.

The spelling of 21112110961 in words is "twenty-one billion, one hundred twelve million, one hundred ten thousand, nine hundred sixty-one".