501689 has 4 divisors (see below), whose sum is σ = 503424. Its totient is φ = 499956.

The previous prime is 501659. The next prime is 501691. The reversal of 501689 is 986105.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 986105 = 5 ⋅197221.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-501689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (501659) 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 in 3 ways as a sum of consecutive naturals, for example, 317 + ... + 1050.

It is an arithmetic number, because the mean of its divisors is an integer number (125856).

2⁵⁰¹⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

501689 is a deficient number, since it is larger than the sum of its proper divisors (1735).

501689 is a wasteful number, since it uses less digits than its factorization.

501689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1734.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 501689 is about 708.3000776507. The cubic root of 501689 is about 79.4593228347.

Subtracting 501689 from its reverse (986105), we obtain a square (484416 = 696²).

The spelling of 501689 in words is "five hundred one thousand, six hundred eighty-nine".