561878 has 4 divisors (see below), whose sum is σ = 842820. Its totient is φ = 280938.

The previous prime is 561839. The next prime is 561907. The reversal of 561878 is 878165.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 878165 = 5 ⋅175633.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140468 + ... + 140471.

It is an arithmetic number, because the mean of its divisors is an integer number (210705).

2⁵⁶¹⁸⁷⁸ is an apocalyptic number.

561878 is a deficient number, since it is larger than the sum of its proper divisors (280942).

561878 is a wasteful number, since it uses less digits than its factorization.

561878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280941.

The product of its digits is 13440, while the sum is 35.

The square root of 561878 is about 749.5852186376. The cubic root of 561878 is about 82.5177433523.

The spelling of 561878 in words is "five hundred sixty-one thousand, eight hundred seventy-eight".