503666 has 4 divisors (see below), whose sum is σ = 755502. Its totient is φ = 251832.

The previous prime is 503663. The next prime is 503707. The reversal of 503666 is 666305.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666305 = 5 ⋅133261.

It can be written as a sum of positive squares in only one way, i.e., 366025 + 137641 = 605^2 + 371^2 .

It is not an unprimeable number, because it can be changed into a prime (503663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125915 + ... + 125918.

2⁵⁰³⁶⁶⁶ is an apocalyptic number.

503666 is a deficient number, since it is larger than the sum of its proper divisors (251836).

503666 is a wasteful number, since it uses less digits than its factorization.

503666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251835.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 503666 is about 709.6943003857. The cubic root of 503666 is about 79.5635608406.

The spelling of 503666 in words is "five hundred three thousand, six hundred sixty-six".