21112302173 has 2 divisors, whose sum is σ = 21112302174. Its totient is φ = 21112302172.

The previous prime is 21112302161. The next prime is 21112302283. The reversal of 21112302173 is 37120321112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20564133604 + 548168569 = 143402^2 + 23413^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112302173 - 2⁶ = 21112302109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112302373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556151086 + 10556151087.

It is an arithmetic number, because the mean of its divisors is an integer number (10556151087).

Almost surely, 2^21112302173 is an apocalyptic number.

It is an amenable number.

21112302173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112302173 is an equidigital number, since it uses as much as digits as its factorization.

21112302173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 23.

Adding to 21112302173 its reverse (37120321112), we get a palindrome (58232623285).

The spelling of 21112302173 in words is "twenty-one billion, one hundred twelve million, three hundred two thousand, one hundred seventy-three".