31121123123 has 4 divisors (see below), whose sum is σ = 31131104160. Its totient is φ = 31111142088.

The previous prime is 31121123113. The next prime is 31121123141. The reversal of 31121123123 is 32132112113.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32132112113 = 367 ⋅87553439.

It is a cyclic number.

It is not a de Polignac number, because 31121123123 - 2²⁸ = 30852687667 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31121123095 and 31121123104.

It is not an unprimeable number, because it can be changed into a prime (31121123113) 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 3 ways as a sum of consecutive naturals, for example, 4985840 + ... + 4992077.

It is an arithmetic number, because the mean of its divisors is an integer number (7782776040).

Almost surely, 2^31121123123 is an apocalyptic number.

31121123123 is a deficient number, since it is larger than the sum of its proper divisors (9981037).

31121123123 is an equidigital number, since it uses as much as digits as its factorization.

31121123123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9981036.

The product of its digits is 216, while the sum is 20.

Adding to 31121123123 its reverse (32132112113), we get a palindrome (63253235236).

The spelling of 31121123123 in words is "thirty-one billion, one hundred twenty-one million, one hundred twenty-three thousand, one hundred twenty-three".