12640378778873 has 4 divisors (see below), whose sum is σ = 12654315250320. Its totient is φ = 12626442307428.

The previous prime is 12640378778831. The next prime is 12640378778887. The reversal of 12640378778873 is 37887787304621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12640378778873 - 2³⁴ = 12623198909689 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12640378778797 and 12640378778806.

It is not an unprimeable number, because it can be changed into a prime (12640378778803) 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, 6968234363 + ... + 6968236176.

It is an arithmetic number, because the mean of its divisors is an integer number (3163578812580).

Almost surely, 2^{12640378778873} is an apocalyptic number.

It is an amenable number.

12640378778873 is a deficient number, since it is larger than the sum of its proper divisors (13936471447).

12640378778873 is an equidigital number, since it uses as much as digits as its factorization.

12640378778873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13936471446.

The product of its (nonzero) digits is 531062784, while the sum is 71.

The spelling of 12640378778873 in words is "twelve trillion, six hundred forty billion, three hundred seventy-eight million, seven hundred seventy-eight thousand, eight hundred seventy-three".