21225763 has 4 divisors (see below), whose sum is σ = 22858528. Its totient is φ = 19593000.

The previous prime is 21225761. The next prime is 21225769. The reversal of 21225763 is 36752212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21225763 - 2¹ = 21225761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21225761) 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 in 3 ways as a sum of consecutive naturals, for example, 816363 + ... + 816388.

It is an arithmetic number, because the mean of its divisors is an integer number (5714632).

Almost surely, 2^21225763 is an apocalyptic number.

21225763 is a deficient number, since it is larger than the sum of its proper divisors (1632765).

21225763 is a wasteful number, since it uses less digits than its factorization.

21225763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1632764.

The product of its digits is 5040, while the sum is 28.

The square root of 21225763 is about 4607.1426068660. The cubic root of 21225763 is about 276.8775671315.

Adding to 21225763 its reverse (36752212), we get a palindrome (57977975).

The spelling of 21225763 in words is "twenty-one million, two hundred twenty-five thousand, seven hundred sixty-three".