12918280321 has 4 divisors (see below), whose sum is σ = 12918971092. Its totient is φ = 12917589552.

The previous prime is 12918280223. The next prime is 12918280327. The reversal of 12918280321 is 12308281921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12308281921 = 13 ⋅946790917.

It can be written as a sum of positive squares in 2 ways, for example, as 1392110721 + 11526169600 = 37311^2 + 107360^2 .

It is a cyclic number.

It is not a de Polignac number, because 12918280321 - 2²⁹ = 12381409409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12918280327) 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, 316530 + ... + 355003.

It is an arithmetic number, because the mean of its divisors is an integer number (3229742773).

Almost surely, 2^12918280321 is an apocalyptic number.

It is an amenable number.

12918280321 is a deficient number, since it is larger than the sum of its proper divisors (690771).

12918280321 is an equidigital number, since it uses as much as digits as its factorization.

12918280321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690770.

The product of its (nonzero) digits is 13824, while the sum is 37.

The spelling of 12918280321 in words is "twelve billion, nine hundred eighteen million, two hundred eighty thousand, three hundred twenty-one".