206342221 has 4 divisors (see below), whose sum is σ = 213457500. Its totient is φ = 199226944.

The previous prime is 206342207. The next prime is 206342239. The reversal of 206342221 is 122243602.

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 82264900 + 124077321 = 9070^2 + 11139^2 .

It is a cyclic number.

It is not a de Polignac number, because 206342221 - 2⁷ = 206342093 is a prime.

It is a super-2 number, since 2×206342221² = 85154224334425682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 206342192 and 206342201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206342021) 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, 3557596 + ... + 3557653.

It is an arithmetic number, because the mean of its divisors is an integer number (53364375).

Almost surely, 2^206342221 is an apocalyptic number.

It is an amenable number.

206342221 is a deficient number, since it is larger than the sum of its proper divisors (7115279).

206342221 is an equidigital number, since it uses as much as digits as its factorization.

206342221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7115278.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 206342221 is about 14364.6169806229. The cubic root of 206342221 is about 590.9209222311.

Adding to 206342221 its reverse (122243602), we get a palindrome (328585823).

The spelling of 206342221 in words is "two hundred six million, three hundred forty-two thousand, two hundred twenty-one".