1123121999 has 2 divisors, whose sum is σ = 1123122000. Its totient is φ = 1123121998.

The previous prime is 1123121981. The next prime is 1123122001. The reversal of 1123121999 is 9991213211.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1123121999 - 2⁸ = 1123121743 is a prime.

It is a super-2 number, since 2×1123121999² = 2522806049275512002, which contains 22 as substring.

Together with 1123122001, 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 (1123121959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 561560999 + 561561000.

It is an arithmetic number, because the mean of its divisors is an integer number (561561000).

Almost surely, 2^1123121999 is an apocalyptic number.

1123121999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1123121999 is an equidigital number, since it uses as much as digits as its factorization.

1123121999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8748, while the sum is 38.

The square root of 1123121999 is about 33513.0123832520. The cubic root of 1123121999 is about 1039.4628633462.

The spelling of 1123121999 in words is "one billion, one hundred twenty-three million, one hundred twenty-one thousand, nine hundred ninety-nine".