123131111999 has 8 divisors (see below), whose sum is σ = 140723708928. Its totient is φ = 105539124600.

The previous prime is 123131111989. The next prime is 123131112001. The reversal of 123131111999 is 999111131321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123131111999 - 2¹⁶ = 123131046463 is a prime.

It is a super-2 number, since 2×123131111999² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123131111989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 427754 + ... + 655160.

It is an arithmetic number, because the mean of its divisors is an integer number (17590463616).

Almost surely, 2^123131111999 is an apocalyptic number.

123131111999 is a deficient number, since it is larger than the sum of its proper divisors (17592596929).

123131111999 is an equidigital number, since it uses as much as digits as its factorization.

123131111999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304765.

The product of its digits is 13122, while the sum is 41.

The spelling of 123131111999 in words is "one hundred twenty-three billion, one hundred thirty-one million, one hundred eleven thousand, nine hundred ninety-nine".