501644161 has 4 divisors (see below), whose sum is σ = 503247172. Its totient is φ = 500041152.

The previous prime is 501644153. The next prime is 501644167. The reversal of 501644161 is 161446105.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 161446105 = 5 ⋅32289221.

It can be written as a sum of positive squares in 2 ways, for example, as 97634161 + 404010000 = 9881^2 + 20100^2 .

It is a cyclic number.

It is not a de Polignac number, because 501644161 - 2³ = 501644153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (501644167) 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, 801036 + ... + 801661.

It is an arithmetic number, because the mean of its divisors is an integer number (125811793).

Almost surely, 2^501644161 is an apocalyptic number.

It is an amenable number.

501644161 is a deficient number, since it is larger than the sum of its proper divisors (1603011).

501644161 is a wasteful number, since it uses less digits than its factorization.

501644161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603010.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 501644161 is about 22397.4141587818. The cubic root of 501644161 is about 794.5695550968.

The spelling of 501644161 in words is "five hundred one million, six hundred forty-four thousand, one hundred sixty-one".