1312403123 has 4 divisors (see below), whose sum is σ = 1313747400. Its totient is φ = 1311058848.

The previous prime is 1312403083. The next prime is 1312403173. The reversal of 1312403123 is 3213042131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3213042131 = 13 ⋅247157087.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1312403123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1312403095 and 1312403104.

It is not an unprimeable number, because it can be changed into a prime (1312403173) 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, 670673 + ... + 672626.

It is an arithmetic number, because the mean of its divisors is an integer number (328436850).

Almost surely, 2^1312403123 is an apocalyptic number.

1312403123 is a deficient number, since it is larger than the sum of its proper divisors (1344277).

1312403123 is an equidigital number, since it uses as much as digits as its factorization.

1312403123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344276.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 1312403123 is about 36227.1048111769. The cubic root of 1312403123 is about 1094.8528462345.

Adding to 1312403123 its reverse (3213042131), we get a palindrome (4525445254).

The spelling of 1312403123 in words is "one billion, three hundred twelve million, four hundred three thousand, one hundred twenty-three".