1230238991 has 2 divisors, whose sum is σ = 1230238992. Its totient is φ = 1230238990.

The previous prime is 1230238979. The next prime is 1230239009. The reversal of 1230238991 is 1998320321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1230238991 - 2¹⁴ = 1230222607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1230238921) 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, 615119495 + 615119496.

It is an arithmetic number, because the mean of its divisors is an integer number (615119496).

Almost surely, 2^1230238991 is an apocalyptic number.

1230238991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1230238991 is an equidigital number, since it uses as much as digits as its factorization.

1230238991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 1230238991 is about 35074.7628787423. The cubic root of 1230238991 is about 1071.5106594571.

The spelling of 1230238991 in words is "one billion, two hundred thirty million, two hundred thirty-eight thousand, nine hundred ninety-one".