12784811605 has 4 divisors (see below), whose sum is σ = 15341773932. Its totient is φ = 10227849280.

The previous prime is 12784811591. The next prime is 12784811621. The reversal of 12784811605 is 50611848721.

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 10076545924 + 2708265681 = 100382^2 + 52041^2 .

It is not a de Polignac number, because 12784811605 - 2⁵ = 12784811573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1278481156 + ... + 1278481165.

It is an arithmetic number, because the mean of its divisors is an integer number (3835443483).

Almost surely, 2^12784811605 is an apocalyptic number.

It is an amenable number.

12784811605 is a deficient number, since it is larger than the sum of its proper divisors (2556962327).

12784811605 is an equidigital number, since it uses as much as digits as its factorization.

12784811605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2556962326.

The product of its (nonzero) digits is 107520, while the sum is 43.

The spelling of 12784811605 in words is "twelve billion, seven hundred eighty-four million, eight hundred eleven thousand, six hundred five".