200021 has 4 divisors (see below), whose sum is σ = 201600.
Its totient is φ = 198444.
The previous prime is 200017. The next prime is 200023. The reversal of 200021 is 120002.
Adding to 200021 its reverse (120002), we get a palindrome (320023).
Multipling 200021 by its reverse (120002), we get a palindrome (24002920042).
200021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
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 200021 - 22 = 200017 is a prime.
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 199978 and 200014.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (200023) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 581 + ... + 858.
It is an arithmetic number, because the mean of its divisors is an integer number (50400).
2200021 is an apocalyptic number.
It is an amenable number.
200021 is a deficient number, since it is larger than the sum of its proper divisors (1579).
200021 is a wasteful number, since it uses less digits than its factorization.
200021 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 4, while the sum is 5.
The square root of 200021 is about 447.2370735974.
The cubic root of 200021 is about 58.4824015050.
The spelling of 200021 in words is "two hundred thousand, twenty-one", and thus it is an iban number.