1233109991 has 2 divisors, whose sum is σ = 1233109992. Its totient is φ = 1233109990.

The previous prime is 1233109967. The next prime is 1233109993. The reversal of 1233109991 is 1999013321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1233109991 - 2²⁶ = 1166001127 is a prime.

Together with 1233109993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1233109993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 616554995 + 616554996.

It is an arithmetic number, because the mean of its divisors is an integer number (616554996).

Almost surely, 2^1233109991 is an apocalyptic number.

1233109991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1233109991 is an equidigital number, since it uses as much as digits as its factorization.

1233109991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13122, while the sum is 38.

The square root of 1233109991 is about 35115.6658914508. The cubic root of 1233109991 is about 1072.3435375053.

The spelling of 1233109991 in words is "one billion, two hundred thirty-three million, one hundred nine thousand, nine hundred ninety-one".