208830021 has 4 divisors (see below), whose sum is σ = 278440032. Its totient is φ = 139220012.

The previous prime is 208829987. The next prime is 208830031. The reversal of 208830021 is 120038802.

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 208830021 - 2¹¹ = 208827973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 208829973 and 208830000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208830031) 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, 34805001 + ... + 34805006.

It is an arithmetic number, because the mean of its divisors is an integer number (69610008).

Almost surely, 2^208830021 is an apocalyptic number.

It is an amenable number.

208830021 is a deficient number, since it is larger than the sum of its proper divisors (69610011).

208830021 is an equidigital number, since it uses as much as digits as its factorization.

208830021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69610010.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 208830021 is about 14450.9522523604. The cubic root of 208830021 is about 593.2862875279.

Adding to 208830021 its reverse (120038802), we get a palindrome (328868823).

The spelling of 208830021 in words is "two hundred eight million, eight hundred thirty thousand, twenty-one".