21444166 has 16 divisors (see below), whose sum is σ = 33405840. Its totient is φ = 10311840.

The previous prime is 21444161. The next prime is 21444167. The reversal of 21444166 is 66144412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18640 + ... + 19756.

It is an arithmetic number, because the mean of its divisors is an integer number (2087865).

Almost surely, 2^21444166 is an apocalyptic number.

21444166 is a deficient number, since it is larger than the sum of its proper divisors (11961674).

21444166 is a wasteful number, since it uses less digits than its factorization.

21444166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1479.

The product of its digits is 4608, while the sum is 28.

The square root of 21444166 is about 4630.7845987478. The cubic root of 21444166 is about 277.8239746218.

Adding to 21444166 its reverse (66144412), we get a palindrome (87588578).

The spelling of 21444166 in words is "twenty-one million, four hundred forty-four thousand, one hundred sixty-six".