2168778613 has 4 divisors (see below), whose sum is σ = 2189047680. Its totient is φ = 2148509548.

The previous prime is 2168778571. The next prime is 2168778673. The reversal of 2168778613 is 3168778612.

It is a happy number.

2168778613 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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2168778613 is a prime.

It is a Smith number, since the sum of its digits (49) 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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (2168778673) 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, 10134373 + ... + 10134586.

It is an arithmetic number, because the mean of its divisors is an integer number (547261920).

Almost surely, 2^2168778613 is an apocalyptic number.

It is an amenable number.

2168778613 is a deficient number, since it is larger than the sum of its proper divisors (20269067).

2168778613 is a wasteful number, since it uses less digits than its factorization.

2168778613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20269066.

The product of its digits is 677376, while the sum is 49.

The square root of 2168778613 is about 46570.1472297436. The cubic root of 2168778613 is about 1294.4096458935.

Subtracting 2168778613 from its reverse (3168778612), we obtain a palindrome (999999999).

The spelling of 2168778613 in words is "two billion, one hundred sixty-eight million, seven hundred seventy-eight thousand, six hundred thirteen".