21174224 has 10 divisors (see below), whose sum is σ = 41025090. Its totient is φ = 10587104.

The previous prime is 21174221. The next prime is 21174229. The reversal of 21174224 is 42247112.

It can be written as a sum of positive squares in only one way, i.e., 18215824 + 2958400 = 4268^2 + 1720^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21174224.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21174221) 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 as a sum of consecutive naturals, namely, 661679 + ... + 661710.

It is an arithmetic number, because the mean of its divisors is an integer number (4102509).

Almost surely, 2^21174224 is an apocalyptic number.

It is an amenable number.

21174224 is a deficient number, since it is larger than the sum of its proper divisors (19850866).

21174224 is a wasteful number, since it uses less digits than its factorization.

21174224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323397 (or 1323391 counting only the distinct ones).

The product of its digits is 896, while the sum is 23.

The square root of 21174224 is about 4601.5458272194. The cubic root of 21174224 is about 276.6532868806.

The spelling of 21174224 in words is "twenty-one million, one hundred seventy-four thousand, two hundred twenty-four".