561866878 has 32 divisors (see below), whose sum is σ = 891095040. Its totient is φ = 265356000.

The previous prime is 561866831. The next prime is 561866933. The reversal of 561866878 is 878668165.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 479233 + ... + 480403.

It is an arithmetic number, because the mean of its divisors is an integer number (27846720).

Almost surely, 2^561866878 is an apocalyptic number.

561866878 is a deficient number, since it is larger than the sum of its proper divisors (329228162).

561866878 is a wasteful number, since it uses less digits than its factorization.

561866878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1384.

The product of its digits is 3870720, while the sum is 55.

The square root of 561866878 is about 23703.7313096483. The cubic root of 561866878 is about 825.1719888749.

The spelling of 561866878 in words is "five hundred sixty-one million, eight hundred sixty-six thousand, eight hundred seventy-eight".