1323199991 has 2 divisors, whose sum is σ = 1323199992. Its totient is φ = 1323199990.

The previous prime is 1323199987. The next prime is 1323200003. The reversal of 1323199991 is 1999913231.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1323199991 - 2² = 1323199987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1323199921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 661599995 + 661599996.

It is an arithmetic number, because the mean of its divisors is an integer number (661599996).

Almost surely, 2^1323199991 is an apocalyptic number.

1323199991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1323199991 is an equidigital number, since it uses as much as digits as its factorization.

1323199991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 118098, while the sum is 47.

The square root of 1323199991 is about 36375.8160183383. The cubic root of 1323199991 is about 1097.8470260330.

The spelling of 1323199991 in words is "one billion, three hundred twenty-three million, one hundred ninety-nine thousand, nine hundred ninety-one".