21227504 has 20 divisors (see below), whose sum is σ = 42132720. Its totient is φ = 10354560.

The previous prime is 21227501. The next prime is 21227513. The reversal of 21227504 is 40572212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21227504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21227501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15524 + ... + 16835.

It is an arithmetic number, because the mean of its divisors is an integer number (2106636).

Almost surely, 2^21227504 is an apocalyptic number.

It is an amenable number.

21227504 is a deficient number, since it is larger than the sum of its proper divisors (20905216).

21227504 is a wasteful number, since it uses less digits than its factorization.

21227504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32408 (or 32402 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21227504 is about 4607.3315487384. The cubic root of 21227504 is about 276.8851370308.

Adding to 21227504 its reverse (40572212), we get a palindrome (61799716).

The spelling of 21227504 in words is "twenty-one million, two hundred twenty-seven thousand, five hundred four".