501666 has 24 divisors (see below), whose sum is σ = 1104432. Its totient is φ = 151800.

The previous prime is 501659. The next prime is 501691. The reversal of 501666 is 666105.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 501666.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 381 + ... + 1071.

It is an arithmetic number, because the mean of its divisors is an integer number (46018).

2⁵⁰¹⁶⁶⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 501666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (552216).

501666 is an abundant number, since it is smaller than the sum of its proper divisors (602766).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

501666 is a wasteful number, since it uses less digits than its factorization.

501666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718 (or 707 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 501666 is about 708.2838414082. The cubic root of 501666 is about 79.4581085417.

The spelling of 501666 in words is "five hundred one thousand, six hundred sixty-six".