12905840641 has 4 divisors (see below), whose sum is σ = 13220617284. Its totient is φ = 12591064000.

The previous prime is 12905840603. The next prime is 12905840669. The reversal of 12905840641 is 14604850921.

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

It can be written as a sum of positive squares in 2 ways, for example, as 513475600 + 12392365041 = 22660^2 + 111321^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12905840641 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12905840594 and 12905840603.

It is not an unprimeable number, because it can be changed into a prime (12905844641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157388260 + ... + 157388341.

It is an arithmetic number, because the mean of its divisors is an integer number (3305154321).

Almost surely, 2^12905840641 is an apocalyptic number.

It is an amenable number.

12905840641 is a deficient number, since it is larger than the sum of its proper divisors (314776643).

12905840641 is an equidigital number, since it uses as much as digits as its factorization.

12905840641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314776642.

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 12905840641 in words is "twelve billion, nine hundred five million, eight hundred forty thousand, six hundred forty-one".