561808213 has 4 divisors (see below), whose sum is σ = 581180940. Its totient is φ = 542435488.

The previous prime is 561808211. The next prime is 561808229. The reversal of 561808213 is 312808165.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 290975364 + 270832849 = 17058^2 + 16457^2 .

It is not a de Polignac number, because 561808213 - 2¹ = 561808211 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 (561808211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9686320 + ... + 9686377.

It is an arithmetic number, because the mean of its divisors is an integer number (145295235).

Almost surely, 2^561808213 is an apocalyptic number.

It is an amenable number.

561808213 is a deficient number, since it is larger than the sum of its proper divisors (19372727).

561808213 is a wasteful number, since it uses less digits than its factorization.

561808213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19372726.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 561808213 is about 23702.4938139429. The cubic root of 561808213 is about 825.1432689049.

The spelling of 561808213 in words is "five hundred sixty-one million, eight hundred eight thousand, two hundred thirteen".