561814891 has 8 divisors (see below), whose sum is σ = 632659968. Its totient is φ = 494265000.

The previous prime is 561814889. The next prime is 561814921. The reversal of 561814891 is 198418165.

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 561814891 - 2¹ = 561814889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561814811) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 823435 + ... + 824116.

It is an arithmetic number, because the mean of its divisors is an integer number (79082496).

Almost surely, 2^561814891 is an apocalyptic number.

561814891 is a deficient number, since it is larger than the sum of its proper divisors (70845077).

561814891 is a wasteful number, since it uses less digits than its factorization.

561814891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647593.

The product of its digits is 69120, while the sum is 43.

The square root of 561814891 is about 23702.6346847771. The cubic root of 561814891 is about 825.1465382798.

The spelling of 561814891 in words is "five hundred sixty-one million, eight hundred fourteen thousand, eight hundred ninety-one".