21325563 has 24 divisors (see below), whose sum is σ = 35694048. Its totient is φ = 12016512.

The previous prime is 21325553. The next prime is 21325567. The reversal of 21325563 is 36552312.

It is not a de Polignac number, because 21325563 - 2⁸ = 21325307 is a prime.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (21325567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2281 + ... + 6917.

It is an arithmetic number, because the mean of its divisors is an integer number (1487252).

Almost surely, 2^21325563 is an apocalyptic number.

21325563 is a deficient number, since it is larger than the sum of its proper divisors (14368485).

21325563 is a wasteful number, since it uses less digits than its factorization.

21325563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4723 (or 4720 counting only the distinct ones).

The product of its digits is 5400, while the sum is 27.

The square root of 21325563 is about 4617.9609136501. The cubic root of 21325563 is about 277.3108328498.

Adding to 21325563 its reverse (36552312), we get a palindrome (57877875).

The spelling of 21325563 in words is "twenty-one million, three hundred twenty-five thousand, five hundred sixty-three".