561530000 has 100 divisors (see below), whose sum is σ = 1371020508. Its totient is φ = 222720000.

The previous prime is 561529999. The next prime is 561530023. The reversal of 561530000 is 35165.

It can be written as a sum of positive squares in 10 ways, for example, as 444197776 + 117332224 = 21076^2 + 10832^2 .

It is a tau number, because it is divible by the number of its divisors (100).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2329880 + ... + 2330120.

Almost surely, 2^561530000 is an apocalyptic number.

561530000 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561530000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (685510254).

561530000 is an abundant number, since it is smaller than the sum of its proper divisors (809490508).

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

561530000 is a wasteful number, since it uses less digits than its factorization.

561530000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502 (or 481 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 561530000 is about 23696.6242321559. The cubic root of 561530000 is about 825.0070400379.

Adding to 561530000 its reverse (35165), we get a palindrome (561565165).

The spelling of 561530000 in words is "five hundred sixty-one million, five hundred thirty thousand".