1243312123 has 4 divisors (see below), whose sum is σ = 1243845568. Its totient is φ = 1242778680.

The previous prime is 1243312069. The next prime is 1243312163. The reversal of 1243312123 is 3212133421.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243312123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1243312094 and 1243312103.

It is not an unprimeable number, because it can be changed into a prime (1243312163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263211 + ... + 267892.

It is an arithmetic number, because the mean of its divisors is an integer number (310961392).

Almost surely, 2^1243312123 is an apocalyptic number.

1243312123 is a deficient number, since it is larger than the sum of its proper divisors (533445).

1243312123 is an equidigital number, since it uses as much as digits as its factorization.

1243312123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533444.

The product of its digits is 864, while the sum is 22.

The square root of 1243312123 is about 35260.6313471554. The cubic root of 1243312123 is about 1075.2927626638.

Adding to 1243312123 its reverse (3212133421), we get a palindrome (4455445544).

The spelling of 1243312123 in words is "one billion, two hundred forty-three million, three hundred twelve thousand, one hundred twenty-three".