1279312643 has 4 divisors (see below), whose sum is σ = 1462071600. Its totient is φ = 1096553688.

The previous prime is 1279312637. The next prime is 1279312667. The reversal of 1279312643 is 3462139721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3462139721 = 103 ⋅33613007.

It is a cyclic number.

It is not a de Polignac number, because 1279312643 - 2¹⁸ = 1279050499 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1279312597 and 1279312606.

It is not an unprimeable number, because it can be changed into a prime (1279314643) 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, 91379468 + ... + 91379481.

It is an arithmetic number, because the mean of its divisors is an integer number (365517900).

Almost surely, 2^1279312643 is an apocalyptic number.

1279312643 is a deficient number, since it is larger than the sum of its proper divisors (182758957).

1279312643 is an equidigital number, since it uses as much as digits as its factorization.

1279312643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182758956.

The product of its digits is 54432, while the sum is 38.

The square root of 1279312643 is about 35767.4802439311. The cubic root of 1279312643 is about 1085.5726603857.

The spelling of 1279312643 in words is "one billion, two hundred seventy-nine million, three hundred twelve thousand, six hundred forty-three".