21225356 has 18 divisors (see below), whose sum is σ = 39204900. Its totient is φ = 10053432.

The previous prime is 21225353. The next prime is 21225397. The reversal of 21225356 is 65352212.

It is not an unprimeable number, because it can be changed into a prime (21225353) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5906 + ... + 8793.

It is an arithmetic number, because the mean of its divisors is an integer number (2178050).

Almost surely, 2^21225356 is an apocalyptic number.

It is an amenable number.

21225356 is a deficient number, since it is larger than the sum of its proper divisors (17979544).

21225356 is a wasteful number, since it uses less digits than its factorization.

21225356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14741 (or 14720 counting only the distinct ones).

The product of its digits is 3600, while the sum is 26.

The square root of 21225356 is about 4607.0984361092. The cubic root of 21225356 is about 276.8757974285.

Adding to 21225356 its reverse (65352212), we get a palindrome (86577568).

The spelling of 21225356 in words is "twenty-one million, two hundred twenty-five thousand, three hundred fifty-six".