1231211329 has 2 divisors, whose sum is σ = 1231211330. Its totient is φ = 1231211328.

The previous prime is 1231211309. The next prime is 1231211339. The reversal of 1231211329 is 9231121321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1138050225 + 93161104 = 33735^2 + 9652^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231211329 - 2¹¹ = 1231209281 is a prime.

It is not a weakly prime, because it can be changed into another prime (1231211309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615605664 + 615605665.

It is an arithmetic number, because the mean of its divisors is an integer number (615605665).

Almost surely, 2^1231211329 is an apocalyptic number.

It is an amenable number.

1231211329 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231211329 is an equidigital number, since it uses as much as digits as its factorization.

1231211329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 25.

The square root of 1231211329 is about 35088.6210757847. The cubic root of 1231211329 is about 1071.7928800049.

The spelling of 1231211329 in words is "one billion, two hundred thirty-one million, two hundred eleven thousand, three hundred twenty-nine".