21227445 has 12 divisors (see below), whose sum is σ = 36794316. Its totient is φ = 11321280.

The previous prime is 21227419. The next prime is 21227447. The reversal of 21227445 is 54472212.

21227445 is a `hidden beast` number, since 212 + 2 + 7 + 445 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 9998244 + 11229201 = 3162^2 + 3351^2 .

It is not a de Polignac number, because 21227445 - 2⁷ = 21227317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21227447) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 235816 + ... + 235905.

It is an arithmetic number, because the mean of its divisors is an integer number (3066193).

Almost surely, 2^21227445 is an apocalyptic number.

It is an amenable number.

21227445 is a deficient number, since it is larger than the sum of its proper divisors (15566871).

21227445 is a wasteful number, since it uses less digits than its factorization.

21227445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471732 (or 471729 counting only the distinct ones).

The product of its digits is 4480, while the sum is 27.

The square root of 21227445 is about 4607.3251458954. The cubic root of 21227445 is about 276.8848805045.

Adding to 21227445 its reverse (54472212), we get a palindrome (75699657).

The spelling of 21227445 in words is "twenty-one million, two hundred twenty-seven thousand, four hundred forty-five".