506921 has 4 divisors (see below), whose sum is σ = 508500. Its totient is φ = 505344.

The previous prime is 506911. The next prime is 506929. The reversal of 506921 is 129605.

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

It can be written as a sum of positive squares in 2 ways, for example, as 160000 + 346921 = 400^2 + 589^2 .

It is a cyclic number.

It is not a de Polignac number, because 506921 - 2¹⁴ = 490537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (506929) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 116 + ... + 1013.

It is an arithmetic number, because the mean of its divisors is an integer number (127125).

2⁵⁰⁶⁹²¹ is an apocalyptic number.

It is an amenable number.

506921 is a deficient number, since it is larger than the sum of its proper divisors (1579).

506921 is a wasteful number, since it uses less digits than its factorization.

506921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1578.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 506921 is about 711.9838481314. The cubic root of 506921 is about 79.7345891875.

Adding to 506921 its sum of digits (23), we get a square (506944 = 712²).

The spelling of 506921 in words is "five hundred six thousand, nine hundred twenty-one".