213123872173 has 2 divisors, whose sum is σ = 213123872174. Its totient is φ = 213123872172.

The previous prime is 213123872147. The next prime is 213123872177. The reversal of 213123872173 is 371278321312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 143911733449 + 69212138724 = 379357^2 + 263082^2 .

It is a cyclic number.

It is not a de Polignac number, because 213123872173 - 2²⁹ = 212587001261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213123872177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106561936086 + 106561936087.

It is an arithmetic number, because the mean of its divisors is an integer number (106561936087).

Almost surely, 2^213123872173 is an apocalyptic number.

It is an amenable number.

213123872173 is a deficient number, since it is larger than the sum of its proper divisors (1).

213123872173 is an equidigital number, since it uses as much as digits as its factorization.

213123872173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 40.

The spelling of 213123872173 in words is "two hundred thirteen billion, one hundred twenty-three million, eight hundred seventy-two thousand, one hundred seventy-three".