21244166 has 16 divisors (see below), whose sum is σ = 33730560. Its totient is φ = 10006920.

The previous prime is 21244163. The next prime is 21244177. The reversal of 21244166 is 66144212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244163) 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, 5795 + ... + 8721.

It is an arithmetic number, because the mean of its divisors is an integer number (2108160).

Almost surely, 2^21244166 is an apocalyptic number.

21244166 is a deficient number, since it is larger than the sum of its proper divisors (12486394).

21244166 is a wasteful number, since it uses less digits than its factorization.

21244166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3139.

The product of its digits is 2304, while the sum is 26.

The square root of 21244166 is about 4609.1393990636. The cubic root of 21244166 is about 276.9575627795.

Adding to 21244166 its reverse (66144212), we get a palindrome (87388378).

The spelling of 21244166 in words is "twenty-one million, two hundred forty-four thousand, one hundred sixty-six".