2678784561 has 32 divisors (see below), whose sum is σ = 4043590400. Its totient is φ = 1752243840.

The previous prime is 2678784523. The next prime is 2678784613. The reversal of 2678784561 is 1654878762.

2678784561 is a `hidden beast` number, since 2 + 6 + 7 + 8 + 78 + 4 + 561 = 666.

It is not a de Polignac number, because 2678784561 - 2²³ = 2670395953 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2678784498 and 2678784507.

It is not an unprimeable number, because it can be changed into a prime (2678784461) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 750900 + ... + 754458.

It is an arithmetic number, because the mean of its divisors is an integer number (126362200).

Almost surely, 2^2678784561 is an apocalyptic number.

It is an amenable number.

2678784561 is a deficient number, since it is larger than the sum of its proper divisors (1364805839).

2678784561 is a wasteful number, since it uses less digits than its factorization.

2678784561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4086 (or 4080 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The square root of 2678784561 is about 51756.9759645982. The cubic root of 2678784561 is about 1388.8198946394.

The spelling of 2678784561 in words is "two billion, six hundred seventy-eight million, seven hundred eighty-four thousand, five hundred sixty-one".