561322818 has 64 divisors (see below), whose sum is σ = 1428480000. Its totient is φ = 160052112.

The previous prime is 561322807. The next prime is 561322829. The reversal of 561322818 is 818223165.

It is a happy number.

561322818 is a `hidden beast` number, since 5 + 613 + 2 + 28 + 18 = 666.

It is an interprime number because it is at equal distance from previous prime (561322807) and next prime (561322829).

It is a super-2 number, since 2×561322818² = 630166612014922248, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 232783 + ... + 235181.

It is an arithmetic number, because the mean of its divisors is an integer number (22320000).

Almost surely, 2^561322818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561322818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (714240000).

561322818 is an abundant number, since it is smaller than the sum of its proper divisors (867157182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561322818 is a wasteful number, since it uses less digits than its factorization.

561322818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3036 (or 3030 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 561322818 is about 23692.2522779072. The cubic root of 561322818 is about 824.9055627440.

The spelling of 561322818 in words is "five hundred sixty-one million, three hundred twenty-two thousand, eight hundred eighteen".