221219999173 has 2 divisors, whose sum is σ = 221219999174. Its totient is φ = 221219999172.

The previous prime is 221219999153. The next prime is 221219999191. The reversal of 221219999173 is 371999912122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119064333249 + 102155665924 = 345057^2 + 319618^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221219999173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221219999123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110609999586 + 110609999587.

It is an arithmetic number, because the mean of its divisors is an integer number (110609999587).

Almost surely, 2^221219999173 is an apocalyptic number.

It is an amenable number.

221219999173 is a deficient number, since it is larger than the sum of its proper divisors (1).

221219999173 is an equidigital number, since it uses as much as digits as its factorization.

221219999173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1102248, while the sum is 55.

The spelling of 221219999173 in words is "two hundred twenty-one billion, two hundred nineteen million, nine hundred ninety-nine thousand, one hundred seventy-three".