12787813780861 has 4 divisors (see below), whose sum is σ = 14614644320992. Its totient is φ = 10960983240732.

The previous prime is 12787813780801. The next prime is 12787813780879. The reversal of 12787813780861 is 16808731878721.

12787813780861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 12787813780861 - 2¹⁹ = 12787813256573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12787813780801) 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, 913415270055 + ... + 913415270068.

It is an arithmetic number, because the mean of its divisors is an integer number (3653661080248).

Almost surely, 2^{12787813780861} is an apocalyptic number.

It is an amenable number.

12787813780861 is a deficient number, since it is larger than the sum of its proper divisors (1826830540131).

12787813780861 is an equidigital number, since it uses as much as digits as its factorization.

12787813780861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826830540130.

The product of its (nonzero) digits is 50577408, while the sum is 67.

The spelling of 12787813780861 in words is "twelve trillion, seven hundred eighty-seven billion, eight hundred thirteen million, seven hundred eighty thousand, eight hundred sixty-one".