21224132 has 6 divisors (see below), whose sum is σ = 37142238. Its totient is φ = 10612064.

The previous prime is 21224131. The next prime is 21224141. The reversal of 21224132 is 23142212.

It can be written as a sum of positive squares in only one way, i.e., 15241216 + 5982916 = 3904^2 + 2446^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21224132.

It is not an unprimeable number, because it can be changed into a prime (21224131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2653013 + ... + 2653020.

It is an arithmetic number, because the mean of its divisors is an integer number (6190373).

Almost surely, 2^21224132 is an apocalyptic number.

It is an amenable number.

21224132 is a deficient number, since it is larger than the sum of its proper divisors (15918106).

21224132 is a wasteful number, since it uses less digits than its factorization.

21224132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5306037 (or 5306035 counting only the distinct ones).

The product of its digits is 192, while the sum is 17.

The square root of 21224132 is about 4606.9655957040. The cubic root of 21224132 is about 276.8704751387.

Adding to 21224132 its reverse (23142212), we get a palindrome (44366344).

The spelling of 21224132 in words is "twenty-one million, two hundred twenty-four thousand, one hundred thirty-two".