2678678917 has 4 divisors (see below), whose sum is σ = 2688349516. Its totient is φ = 2669008320.

The previous prime is 2678678897. The next prime is 2678678921. The reversal of 2678678917 is 7198768762.

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 669308641 + 2009370276 = 25871^2 + 44826^2 .

It is a cyclic number.

It is not a de Polignac number, because 2678678917 - 2¹⁹ = 2678154629 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 (2678678017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4834884 + ... + 4835437.

It is an arithmetic number, because the mean of its divisors is an integer number (672087379).

Almost surely, 2^2678678917 is an apocalyptic number.

It is an amenable number.

2678678917 is a deficient number, since it is larger than the sum of its proper divisors (9670599).

2678678917 is an equidigital number, since it uses as much as digits as its factorization.

2678678917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9670598.

The product of its digits is 14224896, while the sum is 61.

The square root of 2678678917 is about 51755.9553771351. The cubic root of 2678678917 is about 1388.8016373024.

The spelling of 2678678917 in words is "two billion, six hundred seventy-eight million, six hundred seventy-eight thousand, nine hundred seventeen".