212021100173 has 2 divisors, whose sum is σ = 212021100174. Its totient is φ = 212021100172.

The previous prime is 212021100143. The next prime is 212021100253. The reversal of 212021100173 is 371001120212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189898107529 + 22122992644 = 435773^2 + 148738^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212021100173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212021100103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106010550086 + 106010550087.

It is an arithmetic number, because the mean of its divisors is an integer number (106010550087).

Almost surely, 2^212021100173 is an apocalyptic number.

It is an amenable number.

212021100173 is a deficient number, since it is larger than the sum of its proper divisors (1).

212021100173 is an equidigital number, since it uses as much as digits as its factorization.

212021100173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

Adding to 212021100173 its reverse (371001120212), we get a palindrome (583022220385).

The spelling of 212021100173 in words is "two hundred twelve billion, twenty-one million, one hundred thousand, one hundred seventy-three".