21144806 has 8 divisors (see below), whose sum is σ = 31747224. Its totient is φ = 10562400.

The previous prime is 21144803. The next prime is 21144829. The reversal of 21144806 is 60844112.

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 (21144803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2000 + ... + 6803.

It is an arithmetic number, because the mean of its divisors is an integer number (3968403).

Almost surely, 2^21144806 is an apocalyptic number.

21144806 is a deficient number, since it is larger than the sum of its proper divisors (10602418).

21144806 is a wasteful number, since it uses less digits than its factorization.

21144806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10006.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21144806 is about 4598.3481816844. The cubic root of 21144806 is about 276.5251065300.

Adding to 21144806 its reverse (60844112), we get a palindrome (81988918).

The spelling of 21144806 in words is "twenty-one million, one hundred forty-four thousand, eight hundred six".