501813 has 12 divisors (see below), whose sum is σ = 780780. Its totient is φ = 308736.

The previous prime is 501803. The next prime is 501817. The reversal of 501813 is 318105.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 288369 + 213444 = 537^2 + 462^2 .

It is not a de Polignac number, because 501813 - 2¹³ = 493621 is a prime.

It is a Curzon number.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501817) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2028 + ... + 2261.

It is an arithmetic number, because the mean of its divisors is an integer number (65065).

2⁵⁰¹⁸¹³ is an apocalyptic number.

It is an amenable number.

501813 is a deficient number, since it is larger than the sum of its proper divisors (278967).

501813 is a wasteful number, since it uses less digits than its factorization.

501813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4308 (or 4305 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 501813 is about 708.3876057640. The cubic root of 501813 is about 79.4658688186.

Adding to 501813 its reverse (318105), we get a palindrome (819918).

The spelling of 501813 in words is "five hundred one thousand, eight hundred thirteen".