819222181 has 2 divisors, whose sum is σ = 819222182. Its totient is φ = 819222180.

The previous prime is 819222101. The next prime is 819222227. The reversal of 819222181 is 181222918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 751308100 + 67914081 = 27410^2 + 8241^2 .

It is a cyclic number.

It is not a de Polignac number, because 819222181 - 2²⁹ = 282351269 is a prime.

It is a super-2 number, since 2×819222181² = 1342249963684793522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (819222101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409611090 + 409611091.

It is an arithmetic number, because the mean of its divisors is an integer number (409611091).

Almost surely, 2^819222181 is an apocalyptic number.

It is an amenable number.

819222181 is a deficient number, since it is larger than the sum of its proper divisors (1).

819222181 is an equidigital number, since it uses as much as digits as its factorization.

819222181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 34.

The square root of 819222181 is about 28622.0575954979. The cubic root of 819222181 is about 935.6941211568.

The spelling of 819222181 in words is "eight hundred nineteen million, two hundred twenty-two thousand, one hundred eighty-one".