21244224213 has 28 divisors (see below), whose sum is σ = 31875618060. Its totient is φ = 14152211136.

The previous prime is 21244224179. The next prime is 21244224269. The reversal of 21244224213 is 31242244212.

It is a happy number.

21244224213 is a `hidden beast` number, since 2 + 1 + 2 + 442 + 2 + 4 + 213 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5690891844 + 15553332369 = 75438^2 + 124713^2 .

It is not a de Polignac number, because 21244224213 - 2⁶ = 21244224149 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244224713) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 1031545 + ... + 1051937.

Almost surely, 2^21244224213 is an apocalyptic number.

It is an amenable number.

21244224213 is a deficient number, since it is larger than the sum of its proper divisors (10631393847).

21244224213 is an equidigital number, since it uses as much as digits as its factorization.

21244224213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21840 (or 21825 counting only the distinct ones).

The product of its digits is 6144, while the sum is 27.

Adding to 21244224213 its reverse (31242244212), we get a palindrome (52486468425).

The spelling of 21244224213 in words is "twenty-one billion, two hundred forty-four million, two hundred twenty-four thousand, two hundred thirteen".