66582181 has 2 divisors, whose sum is σ = 66582182. Its totient is φ = 66582180.

The previous prime is 66582179. The next prime is 66582193. The reversal of 66582181 is 18128566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38130625 + 28451556 = 6175^2 + 5334^2 .

It is a cyclic number.

It is not a de Polignac number, because 66582181 - 2¹ = 66582179 is a prime.

It is a super-2 number, since 2×66582181² = 8866373653433522, which contains 22 as substring.

Together with 66582179, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66582181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66582161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33291090 + 33291091.

It is an arithmetic number, because the mean of its divisors is an integer number (33291091).

Almost surely, 2^66582181 is an apocalyptic number.

It is an amenable number.

66582181 is a deficient number, since it is larger than the sum of its proper divisors (1).

66582181 is an equidigital number, since it uses as much as digits as its factorization.

66582181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23040, while the sum is 37.

The square root of 66582181 is about 8159.7904997616. The cubic root of 66582181 is about 405.3087743343.

The spelling of 66582181 in words is "sixty-six million, five hundred eighty-two thousand, one hundred eighty-one".