221121181 has 2 divisors, whose sum is σ = 221121182. Its totient is φ = 221121180.

The previous prime is 221121167. The next prime is 221121209. The reversal of 221121181 is 181121122.

221121181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214183225 + 6937956 = 14635^2 + 2634^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121181 - 2⁷ = 221121053 is a prime.

It is a super-2 number, since 2×221121181² = 97789153373669522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221121281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110560590 + 110560591.

It is an arithmetic number, because the mean of its divisors is an integer number (110560591).

Almost surely, 2^221121181 is an apocalyptic number.

It is an amenable number.

221121181 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121181 is an equidigital number, since it uses as much as digits as its factorization.

221121181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64, while the sum is 19.

The square root of 221121181 is about 14870.1439468487. The cubic root of 221121181 is about 604.7048452151.

The spelling of 221121181 in words is "two hundred twenty-one million, one hundred twenty-one thousand, one hundred eighty-one".