21768206 has 8 divisors (see below), whose sum is σ = 32672640. Its totient is φ = 10877328.

The previous prime is 21768203. The next prime is 21768221. The reversal of 21768206 is 60286712.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768203) 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, 3155 + ... + 7313.

It is an arithmetic number, because the mean of its divisors is an integer number (4084080).

Almost surely, 2^21768206 is an apocalyptic number.

21768206 is a deficient number, since it is larger than the sum of its proper divisors (10904434).

21768206 is a wasteful number, since it uses less digits than its factorization.

21768206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6778.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 21768206 is about 4665.6410063356. The cubic root of 21768206 is about 279.2163718530.

The spelling of 21768206 in words is "twenty-one million, seven hundred sixty-eight thousand, two hundred six".