1221302171 has 2 divisors, whose sum is σ = 1221302172. Its totient is φ = 1221302170.

The previous prime is 1221302153. The next prime is 1221302213. The reversal of 1221302171 is 1712031221.

It is a weak prime.

It is an emirp because it is prime and its reverse (1712031221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221302171 - 2¹⁸ = 1221040027 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1221302101) 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, 610651085 + 610651086.

It is an arithmetic number, because the mean of its divisors is an integer number (610651086).

Almost surely, 2^1221302171 is an apocalyptic number.

1221302171 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221302171 is an equidigital number, since it uses as much as digits as its factorization.

1221302171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 1221302171 is about 34947.1339454325. The cubic root of 1221302171 is about 1068.9097612087.

Adding to 1221302171 its reverse (1712031221), we get a palindrome (2933333392).

The spelling of 1221302171 in words is "one billion, two hundred twenty-one million, three hundred two thousand, one hundred seventy-one".