510661 has 4 divisors (see below), whose sum is σ = 528300. Its totient is φ = 493024.

The previous prime is 510619. The next prime is 510677. The reversal of 510661 is 166015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166015 = 5 ⋅33203.

It can be written as a sum of positive squares in 2 ways, for example, as 324900 + 185761 = 570^2 + 431^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-510661 is a prime.

It is a Duffinian number.

510661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (510611) 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, 8776 + ... + 8833.

It is an arithmetic number, because the mean of its divisors is an integer number (132075).

2⁵¹⁰⁶⁶¹ is an apocalyptic number.

It is an amenable number.

510661 is a deficient number, since it is larger than the sum of its proper divisors (17639).

510661 is a wasteful number, since it uses less digits than its factorization.

510661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17638.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 510661 is about 714.6054855653. The cubic root of 510661 is about 79.9301995331.

Adding to 510661 its reverse (166015), we get a palindrome (676676).

The spelling of 510661 in words is "five hundred ten thousand, six hundred sixty-one".