506561161 has 4 divisors (see below), whose sum is σ = 506825424. Its totient is φ = 506296900.

The previous prime is 506561137. The next prime is 506561179. The reversal of 506561161 is 161165605.

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: 161165605 = 5 ⋅32233121.

It is a cyclic number.

It is not a de Polignac number, because 506561161 - 2¹¹ = 506559113 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (506561101) 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, 129235 + ... + 133096.

It is an arithmetic number, because the mean of its divisors is an integer number (126706356).

Almost surely, 2^506561161 is an apocalyptic number.

It is an amenable number.

506561161 is a deficient number, since it is larger than the sum of its proper divisors (264263).

506561161 is a wasteful number, since it uses less digits than its factorization.

506561161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264262.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 506561161 is about 22506.9136267059. The cubic root of 506561161 is about 797.1571812974.

The spelling of 506561161 in words is "five hundred six million, five hundred sixty-one thousand, one hundred sixty-one".