21440206 has 8 divisors (see below), whose sum is σ = 32376600. Its totient is φ = 10648008.

The previous prime is 21440203. The next prime is 21440207. The reversal of 21440206 is 60204412.

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 (21440203) by changing a digit.

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, 35676 + ... + 36271.

It is an arithmetic number, because the mean of its divisors is an integer number (4047075).

Almost surely, 2^21440206 is an apocalyptic number.

21440206 is a deficient number, since it is larger than the sum of its proper divisors (10936394).

21440206 is a wasteful number, since it uses less digits than its factorization.

21440206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72098.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21440206 is about 4630.3570056746. The cubic root of 21440206 is about 277.8068720578.

Adding to 21440206 its reverse (60204412), we get a palindrome (81644618).

The spelling of 21440206 in words is "twenty-one million, four hundred forty thousand, two hundred six".