510721 has 4 divisors (see below), whose sum is σ = 514132. Its totient is φ = 507312.

The previous prime is 510709. The next prime is 510751. The reversal of 510721 is 127015.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 378225 + 132496 = 615^2 + 364^2 .

It is a cyclic number.

It is not a de Polignac number, because 510721 - 2¹⁷ = 379649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 510695 and 510704.

It is not an unprimeable number, because it can be changed into a prime (510751) 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, 1470 + ... + 1783.

It is an arithmetic number, because the mean of its divisors is an integer number (128533).

2⁵¹⁰⁷²¹ is an apocalyptic number.

It is an amenable number.

510721 is a deficient number, since it is larger than the sum of its proper divisors (3411).

510721 is a wasteful number, since it uses less digits than its factorization.

510721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3410.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 510721 is about 714.6474655381. The cubic root of 510721 is about 79.9333298708.

Adding to 510721 its reverse (127015), we get a palindrome (637736).

The spelling of 510721 in words is "five hundred ten thousand, seven hundred twenty-one".