12147794581 has 4 divisors (see below), whose sum is σ = 13082240332. Its totient is φ = 11213348832.

The previous prime is 12147794569. The next prime is 12147794597. The reversal of 12147794581 is 18549774121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18549774121 = 271 ⋅68449351.

It can be written as a sum of positive squares in 2 ways, for example, as 1992193956 + 10155600625 = 44634^2 + 100775^2 .

It is a cyclic number.

It is not a de Polignac number, because 12147794581 - 2¹⁹ = 12147270293 is a prime.

It is a super-2 number, since 2×12147794581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12147792581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 467222856 + ... + 467222881.

It is an arithmetic number, because the mean of its divisors is an integer number (3270560083).

Almost surely, 2^12147794581 is an apocalyptic number.

It is an amenable number.

12147794581 is a deficient number, since it is larger than the sum of its proper divisors (934445751).

12147794581 is an equidigital number, since it uses as much as digits as its factorization.

12147794581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934445750.

The product of its digits is 564480, while the sum is 49.

The spelling of 12147794581 in words is "twelve billion, one hundred forty-seven million, seven hundred ninety-four thousand, five hundred eighty-one".