21203206 has 8 divisors (see below), whose sum is σ = 31830264. Its totient is φ = 10593120.

The previous prime is 21203197. The next prime is 21203213. The reversal of 21203206 is 60230212.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21203206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 435 + ... + 6526.

It is an arithmetic number, because the mean of its divisors is an integer number (3978783).

Almost surely, 2^21203206 is an apocalyptic number.

21203206 is a deficient number, since it is larger than the sum of its proper divisors (10627058).

21203206 is a wasteful number, since it uses less digits than its factorization.

21203206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8486.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21203206 is about 4604.6939094798. The cubic root of 21203206 is about 276.7794514438.

Adding to 21203206 its reverse (60230212), we get a palindrome (81433418).

The spelling of 21203206 in words is "twenty-one million, two hundred three thousand, two hundred six".