12781758566 has 4 divisors (see below), whose sum is σ = 19172637852. Its totient is φ = 6390879282.

The previous prime is 12781758551. The next prime is 12781758593. The reversal of 12781758566 is 66585718721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66585718721 = 79 ⋅842857199.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3195439640 + ... + 3195439643.

It is an arithmetic number, because the mean of its divisors is an integer number (4793159463).

Almost surely, 2^12781758566 is an apocalyptic number.

12781758566 is a deficient number, since it is larger than the sum of its proper divisors (6390879286).

12781758566 is an equidigital number, since it uses as much as digits as its factorization.

12781758566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6390879285.

The product of its digits is 5644800, while the sum is 56.

The spelling of 12781758566 in words is "twelve billion, seven hundred eighty-one million, seven hundred fifty-eight thousand, five hundred sixty-six".