206421 has 8 divisors (see below), whose sum is σ = 278880. Its totient is φ = 135792.

The previous prime is 206419. The next prime is 206447. The reversal of 206421 is 124602.

206421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 206421 - 2¹ = 206419 is a prime.

206421 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 206421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206411) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166 + ... + 663.

It is an arithmetic number, because the mean of its divisors is an integer number (34860).

2²⁰⁶⁴²¹ is an apocalyptic number.

It is an amenable number.

206421 is a deficient number, since it is larger than the sum of its proper divisors (72459).

206421 is an equidigital number, since it uses as much as digits as its factorization.

206421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 915.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 206421 is about 454.3357789125. The cubic root of 206421 is about 59.0996114850.

It can be divided in two parts, 20 and 6421, that added together give a triangular number (6441 = T₁₁₃).

The spelling of 206421 in words is "two hundred six thousand, four hundred twenty-one".