561878561 has 8 divisors (see below), whose sum is σ = 574855680. Its totient is φ = 548944128.

The previous prime is 561878539. The next prime is 561878563. The reversal of 561878561 is 165878165.

It is a happy number.

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 561878561 - 2⁶ = 561878497 is a prime.

It is a super-2 number, since 2×561878561² = 631415034622861442, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (47).

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561878563) 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, 16760 + ... + 37478.

It is an arithmetic number, because the mean of its divisors is an integer number (71856960).

Almost surely, 2^561878561 is an apocalyptic number.

It is an amenable number.

561878561 is a deficient number, since it is larger than the sum of its proper divisors (12977119).

561878561 is a wasteful number, since it uses less digits than its factorization.

561878561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21343.

The product of its digits is 403200, while the sum is 47.

The square root of 561878561 is about 23703.9777463615. The cubic root of 561878561 is about 825.1777081523.

The spelling of 561878561 in words is "five hundred sixty-one million, eight hundred seventy-eight thousand, five hundred sixty-one".