21210166673 has 2 divisors, whose sum is σ = 21210166674. Its totient is φ = 21210166672.

The previous prime is 21210166667. The next prime is 21210166693. The reversal of 21210166673 is 37666101212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18340743184 + 2869423489 = 135428^2 + 53567^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210166673 - 2¹⁴ = 21210150289 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210166643) 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, 10605083336 + 10605083337.

It is an arithmetic number, because the mean of its divisors is an integer number (10605083337).

Almost surely, 2^21210166673 is an apocalyptic number.

It is an amenable number.

21210166673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210166673 is an equidigital number, since it uses as much as digits as its factorization.

21210166673 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 35.

Adding to 21210166673 its reverse (37666101212), we get a palindrome (58876267885).

The spelling of 21210166673 in words is "twenty-one billion, two hundred ten million, one hundred sixty-six thousand, six hundred seventy-three".