21522040443424 has 12 divisors (see below), whose sum is σ = 42371517123054. Its totient is φ = 10761020221696.

The previous prime is 21522040443401. The next prime is 21522040443427. The reversal of 21522040443424 is 42434404022512.

It can be written as a sum of positive squares in only one way, i.e., 19552138368400 + 1969902075024 = 4421780^2 + 1403532^2 .

It is not an unprimeable number, because it can be changed into a prime (21522040443427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 336281881897 + ... + 336281881960.

Almost surely, 2^{21522040443424} is an apocalyptic number.

It is an amenable number.

21522040443424 is a deficient number, since it is larger than the sum of its proper divisors (20849476679630).

21522040443424 is an equidigital number, since it uses as much as digits as its factorization.

21522040443424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672563763867 (or 672563763859 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 37.

Adding to 21522040443424 its reverse (42434404022512), we get a palindrome (63956444465936).

The spelling of 21522040443424 in words is "twenty-one trillion, five hundred twenty-two billion, forty million, four hundred forty-three thousand, four hundred twenty-four".