501663 has 4 divisors (see below), whose sum is σ = 668888. Its totient is φ = 334440.

The previous prime is 501659. The next prime is 501691. The reversal of 501663 is 366105.

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

It is not a de Polignac number, because 501663 - 2² = 501659 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501623) 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, 83608 + ... + 83613.

It is an arithmetic number, because the mean of its divisors is an integer number (167222).

2⁵⁰¹⁶⁶³ is an apocalyptic number.

501663 is a deficient number, since it is larger than the sum of its proper divisors (167225).

501663 is a wasteful number, since it uses less digits than its factorization.

501663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167224.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 501663 is about 708.2817236100. The cubic root of 501663 is about 79.4579501529.

Adding to 501663 its reverse (366105), we get a palindrome (867768).

The spelling of 501663 in words is "five hundred one thousand, six hundred sixty-three".