561510161 has 4 divisors (see below), whose sum is σ = 579623424. Its totient is φ = 543396900.

The previous prime is 561510149. The next prime is 561510179. The reversal of 561510161 is 161015165.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 161015165 = 5 ⋅32203033.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561510161 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 561510161.

It is not an unprimeable number, because it can be changed into a prime (561510101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9056585 + ... + 9056646.

It is an arithmetic number, because the mean of its divisors is an integer number (144905856).

Almost surely, 2^561510161 is an apocalyptic number.

It is an amenable number.

561510161 is a deficient number, since it is larger than the sum of its proper divisors (18113263).

561510161 is a wasteful number, since it uses less digits than its factorization.

561510161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18113262.

The product of its (nonzero) digits is 900, while the sum is 26.

The square root of 561510161 is about 23696.2056245298. The cubic root of 561510161 is about 824.9973240195.

The spelling of 561510161 in words is "five hundred sixty-one million, five hundred ten thousand, one hundred sixty-one".