866227181 has 2 divisors, whose sum is σ = 866227182. Its totient is φ = 866227180.

The previous prime is 866227171. The next prime is 866227183. The reversal of 866227181 is 181722668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 648517156 + 217710025 = 25466^2 + 14755^2 .

It is a cyclic number.

It is not a de Polignac number, because 866227181 - 2¹⁰ = 866226157 is a prime.

It is a super-4 number, since 4×866227181⁴ (a number of 37 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

Together with 866227183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866227183) 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, 433113590 + 433113591.

It is an arithmetic number, because the mean of its divisors is an integer number (433113591).

Almost surely, 2^866227181 is an apocalyptic number.

It is an amenable number.

866227181 is a deficient number, since it is larger than the sum of its proper divisors (1).

866227181 is an equidigital number, since it uses as much as digits as its factorization.

866227181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 41.

The square root of 866227181 is about 29431.7376483279. The cubic root of 866227181 is about 953.2583154357.

The spelling of 866227181 in words is "eight hundred sixty-six million, two hundred twenty-seven thousand, one hundred eighty-one".