1198333991 has 2 divisors, whose sum is σ = 1198333992. Its totient is φ = 1198333990.

The previous prime is 1198333987. The next prime is 1198333999. The reversal of 1198333991 is 1993338911.

It is a weak prime.

It is an emirp because it is prime and its reverse (1993338911) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1198333991 - 2² = 1198333987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1198333999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 599166995 + 599166996.

It is an arithmetic number, because the mean of its divisors is an integer number (599166996).

Almost surely, 2^1198333991 is an apocalyptic number.

1198333991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1198333991 is an equidigital number, since it uses as much as digits as its factorization.

1198333991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 47.

The square root of 1198333991 is about 34616.9610306855. The cubic root of 1198333991 is about 1062.1665639942.

The spelling of 1198333991 in words is "one billion, one hundred ninety-eight million, three hundred thirty-three thousand, nine hundred ninety-one".