21224166 has 32 divisors (see below), whose sum is σ = 43987968. Its totient is φ = 6822720.

The previous prime is 21224149. The next prime is 21224167. The reversal of 21224166 is 66142212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20071 + ... + 21101.

It is an arithmetic number, because the mean of its divisors is an integer number (1374624).

Almost surely, 2^21224166 is an apocalyptic number.

21224166 is an abundant number, since it is smaller than the sum of its proper divisors (22763802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21224166 is a wasteful number, since it uses less digits than its factorization.

21224166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1156.

The product of its digits is 1152, while the sum is 24.

The square root of 21224166 is about 4606.9692857669. The cubic root of 21224166 is about 276.8706229828.

Adding to 21224166 its reverse (66142212), we get a palindrome (87366378).

The spelling of 21224166 in words is "twenty-one million, two hundred twenty-four thousand, one hundred sixty-six".