561000001 has 4 divisors (see below), whose sum is σ = 566146900. Its totient is φ = 555853104.

The previous prime is 560999977. The next prime is 561000047. The reversal of 561000001 is 100000165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 100000165 = 5 ⋅20000033.

It can be written as a sum of positive squares in 2 ways, for example, as 443060401 + 117939600 = 21049^2 + 10860^2 .

It is a cyclic number.

It is not a de Polignac number, because 561000001 - 2¹⁵ = 560967233 is a prime.

It is a super-2 number, since 2×561000001² = 629442002244000002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561000091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2573286 + ... + 2573503.

It is an arithmetic number, because the mean of its divisors is an integer number (141536725).

Almost surely, 2^561000001 is an apocalyptic number.

It is an amenable number.

561000001 is a deficient number, since it is larger than the sum of its proper divisors (5146899).

561000001 is a wasteful number, since it uses less digits than its factorization.

561000001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5146898.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 561000001 is about 23685.4385857640. The cubic root of 561000001 is about 824.7473979023.

Adding to 561000001 its reverse (100000165), we get a palindrome (661000166).

The spelling of 561000001 in words is "five hundred sixty-one million, one", and thus it is an aban number.