550021 has 4 divisors (see below), whose sum is σ = 552672. Its totient is φ = 547372.

The previous prime is 550009. The next prime is 550027. The reversal of 550021 is 120055.

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.

It is a cyclic number.

It is not a de Polignac number, because 550021 - 2⁹ = 549509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 549983 and 550010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (550027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 985 + ... + 1438.

It is an arithmetic number, because the mean of its divisors is an integer number (138168).

2⁵⁵⁰⁰²¹ is an apocalyptic number.

It is an amenable number.

550021 is a deficient number, since it is larger than the sum of its proper divisors (2651).

550021 is a wasteful number, since it uses less digits than its factorization.

550021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2650.

The product of its (nonzero) digits is 50, while the sum is 13.

The square root of 550021 is about 741.6340067715. The cubic root of 550021 is about 81.9331698193.

Adding to 550021 its reverse (120055), we get a palindrome (670076).

The spelling of 550021 in words is "five hundred fifty thousand, twenty-one".