221043181 has 2 divisors, whose sum is σ = 221043182. Its totient is φ = 221043180.

The previous prime is 221043127. The next prime is 221043223. The reversal of 221043181 is 181340122.

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., 203319081 + 17724100 = 14259^2 + 4210^2 .

It is a cyclic number.

It is not a de Polignac number, because 221043181 - 2²¹ = 218946029 is a prime.

It is a super-2 number, since 2×221043181² = 97720175733197522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221043101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110521590 + 110521591.

It is an arithmetic number, because the mean of its divisors is an integer number (110521591).

Almost surely, 2^221043181 is an apocalyptic number.

It is an amenable number.

221043181 is a deficient number, since it is larger than the sum of its proper divisors (1).

221043181 is an equidigital number, since it uses as much as digits as its factorization.

221043181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 221043181 is about 14867.5210105787. The cubic root of 221043181 is about 604.6337340943.

The spelling of 221043181 in words is "two hundred twenty-one million, forty-three thousand, one hundred eighty-one".