561809813 has 8 divisors (see below), whose sum is σ = 582390432. Its totient is φ = 541513296.

The previous prime is 561809789. The next prime is 561809861. The reversal of 561809813 is 318908165.

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 561809813 - 2¹⁰ = 561808789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561809893) 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, 66995 + ... + 74912.

It is an arithmetic number, because the mean of its divisors is an integer number (72798804).

Almost surely, 2^561809813 is an apocalyptic number.

It is an amenable number.

561809813 is a deficient number, since it is larger than the sum of its proper divisors (20580619).

561809813 is a wasteful number, since it uses less digits than its factorization.

561809813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142051.

The product of its (nonzero) digits is 51840, while the sum is 41.

The square root of 561809813 is about 23702.5275656416. The cubic root of 561809813 is about 825.1440522256.

The spelling of 561809813 in words is "five hundred sixty-one million, eight hundred nine thousand, eight hundred thirteen".