21223376 has 10 divisors (see below), whose sum is σ = 41120322. Its totient is φ = 10611680.

The previous prime is 21223369. The next prime is 21223379. The reversal of 21223376 is 67332212.

It can be written as a sum of positive squares in only one way, i.e., 12673600 + 8549776 = 3560^2 + 2924^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663215 + ... + 663246.

Almost surely, 2^21223376 is an apocalyptic number.

It is an amenable number.

21223376 is a deficient number, since it is larger than the sum of its proper divisors (19896946).

21223376 is a wasteful number, since it uses less digits than its factorization.

21223376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326469 (or 1326463 counting only the distinct ones).

The product of its digits is 3024, while the sum is 26.

The square root of 21223376 is about 4606.8835453048. The cubic root of 21223376 is about 276.8671877398.

Adding to 21223376 its reverse (67332212), we get a palindrome (88555588).

The spelling of 21223376 in words is "twenty-one million, two hundred twenty-three thousand, three hundred seventy-six".