2778555787681 has 8 divisors (see below), whose sum is σ = 2930752389600. Its totient is φ = 2626954868160.

The previous prime is 2778555787633. The next prime is 2778555787697. The reversal of 2778555787681 is 1867875558772.

2778555787681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2778555787681 - 2⁹ = 2778555787169 is a prime.

It is a super-3 number, since 3×2778555787681³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2778555787598 and 2778555787607.

It is not an unprimeable number, because it can be changed into a prime (2778555787621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148911016 + ... + 148929673.

It is an arithmetic number, because the mean of its divisors is an integer number (366344048700).

Almost surely, 2^{2778555787681} is an apocalyptic number.

It is an amenable number.

2778555787681 is a deficient number, since it is larger than the sum of its proper divisors (152196601919).

2778555787681 is a wasteful number, since it uses less digits than its factorization.

2778555787681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297841199.

The product of its digits is 1843968000, while the sum is 76.

The spelling of 2778555787681 in words is "two trillion, seven hundred seventy-eight billion, five hundred fifty-five million, seven hundred eighty-seven thousand, six hundred eighty-one".