500661 has 20 divisors (see below), whose sum is σ = 855712. Its totient is φ = 285768.

The previous prime is 500629. The next prime is 500671. The reversal of 500661 is 166005.

500661 is a `hidden beast` number, since 5 + 0 + 0 + 661 = 666.

It is not a de Polignac number, because 500661 - 2⁵ = 500629 is a prime.

It is a super-2 number, since 2×500661² = 501322873842, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (500671) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 126 + ... + 1008.

2⁵⁰⁰⁶⁶¹ is an apocalyptic number.

It is an amenable number.

500661 is a deficient number, since it is larger than the sum of its proper divisors (355051).

500661 is an equidigital number, since it uses as much as digits as its factorization.

500661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 902 (or 893 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 500661 is about 707.5740243960. The cubic root of 500661 is about 79.4050129336.

Adding to 500661 its reverse (166005), we get a palindrome (666666).

The spelling of 500661 in words is "five hundred thousand, six hundred sixty-one".