21012206 has 8 divisors (see below), whose sum is σ = 31824624. Its totient is φ = 10404000.

The previous prime is 21012193. The next prime is 21012227. The reversal of 21012206 is 60221012.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50795 + ... + 51206.

It is an arithmetic number, because the mean of its divisors is an integer number (3978078).

Almost surely, 2^21012206 is an apocalyptic number.

21012206 is a deficient number, since it is larger than the sum of its proper divisors (10812418).

21012206 is a wasteful number, since it uses less digits than its factorization.

21012206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102106.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21012206 is about 4583.9072852753. The cubic root of 21012206 is about 275.9458603462.

Adding to 21012206 its reverse (60221012), we get a palindrome (81233218).

The spelling of 21012206 in words is "twenty-one million, twelve thousand, two hundred six".