21212200220173 has 2 divisors, whose sum is σ = 21212200220174. Its totient is φ = 21212200220172.

The previous prime is 21212200220093. The next prime is 21212200220179. The reversal of 21212200220173 is 37102200221212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11055505300324 + 10156694919849 = 3324982^2 + 3186957^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212200220173 - 2³³ = 21203610285581 is a prime.

It is a super-2 number, since 2×21212200220173² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212200220179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606100110086 + 10606100110087.

It is an arithmetic number, because the mean of its divisors is an integer number (10606100110087).

Almost surely, 2^{21212200220173} is an apocalyptic number.

It is an amenable number.

21212200220173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212200220173 is an equidigital number, since it uses as much as digits as its factorization.

21212200220173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 25.

Adding to 21212200220173 its reverse (37102200221212), we get a palindrome (58314400441385).

The spelling of 21212200220173 in words is "twenty-one trillion, two hundred twelve billion, two hundred million, two hundred twenty thousand, one hundred seventy-three".