1206618221 has 2 divisors, whose sum is σ = 1206618222. Its totient is φ = 1206618220.

The previous prime is 1206618187. The next prime is 1206618229. The reversal of 1206618221 is 1228166021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 860248900 + 346369321 = 29330^2 + 18611^2 .

It is a cyclic number.

It is not a de Polignac number, because 1206618221 - 2¹⁸ = 1206356077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1206618229) 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, 603309110 + 603309111.

It is an arithmetic number, because the mean of its divisors is an integer number (603309111).

Almost surely, 2^1206618221 is an apocalyptic number.

It is an amenable number.

1206618221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1206618221 is an equidigital number, since it uses as much as digits as its factorization.

1206618221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 1206618221 is about 34736.4105946484. The cubic root of 1206618221 is about 1064.6085745896.

The spelling of 1206618221 in words is "one billion, two hundred six million, six hundred eighteen thousand, two hundred twenty-one".