211220220173 has 2 divisors, whose sum is σ = 211220220174. Its totient is φ = 211220220172.

The previous prime is 211220220137. The next prime is 211220220179. The reversal of 211220220173 is 371022022112.

Together with previous prime (211220220137) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211220210569 + 9604 = 459587^2 + 98^2 .

It is a cyclic number.

It is not a de Polignac number, because 211220220173 - 2³⁴ = 194040350989 is a prime.

It is a super-2 number, since 2×211220220173² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211220220179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610110086 + 105610110087.

It is an arithmetic number, because the mean of its divisors is an integer number (105610110087).

Almost surely, 2^211220220173 is an apocalyptic number.

It is an amenable number.

211220220173 is a deficient number, since it is larger than the sum of its proper divisors (1).

211220220173 is an equidigital number, since it uses as much as digits as its factorization.

211220220173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

Adding to 211220220173 its reverse (371022022112), we get a palindrome (582242242285).

The spelling of 211220220173 in words is "two hundred eleven billion, two hundred twenty million, two hundred twenty thousand, one hundred seventy-three".