2878638561 has 8 divisors (see below), whose sum is σ = 4264649760. Its totient is φ = 1919092356.

The previous prime is 2878638559. The next prime is 2878638589. The reversal of 2878638561 is 1658368782.

2878638561 is a `hidden beast` number, since 2 + 8 + 78 + 6 + 3 + 8 + 561 = 666.

It is not a de Polignac number, because 2878638561 - 2¹ = 2878638559 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2878638498 and 2878638507.

It is not an unprimeable number, because it can be changed into a prime (2878638461) 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, 53308095 + ... + 53308148.

It is an arithmetic number, because the mean of its divisors is an integer number (533081220).

Almost surely, 2^2878638561 is an apocalyptic number.

It is an amenable number.

2878638561 is a deficient number, since it is larger than the sum of its proper divisors (1386011199).

2878638561 is a wasteful number, since it uses less digits than its factorization.

2878638561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106616252 (or 106616246 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 54.

The square root of 2878638561 is about 53652.9455016218. The cubic root of 2878638561 is about 1422.5330969574.

The spelling of 2878638561 in words is "two billion, eight hundred seventy-eight million, six hundred thirty-eight thousand, five hundred sixty-one".