21066105173 has 2 divisors, whose sum is σ = 21066105174. Its totient is φ = 21066105172.

The previous prime is 21066105139. The next prime is 21066105233. The reversal of 21066105173 is 37150166012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10698385489 + 10367719684 = 103433^2 + 101822^2 .

It is a cyclic number.

It is not a de Polignac number, because 21066105173 - 2¹⁴ = 21066088789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21066105113) 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, 10533052586 + 10533052587.

It is an arithmetic number, because the mean of its divisors is an integer number (10533052587).

Almost surely, 2^21066105173 is an apocalyptic number.

It is an amenable number.

21066105173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21066105173 is an equidigital number, since it uses as much as digits as its factorization.

21066105173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 32.

The spelling of 21066105173 in words is "twenty-one billion, sixty-six million, one hundred five thousand, one hundred seventy-three".