21224152505521 has 8 divisors (see below), whose sum is σ = 24256774525824. Its totient is φ = 18191680543680.

The previous prime is 21224152505519. The next prime is 21224152505551. The reversal of 21224152505521 is 12550525142212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21224152505521 - 2¹ = 21224152505519 is a prime.

It is a super-2 number, since 2×21224152505521² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21224152505551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37211365 + ... + 37777426.

It is an arithmetic number, because the mean of its divisors is an integer number (3032096815728).

Almost surely, 2^{21224152505521} is an apocalyptic number.

It is an amenable number.

21224152505521 is a deficient number, since it is larger than the sum of its proper divisors (3032622020303).

21224152505521 is an equidigital number, since it uses as much as digits as its factorization.

21224152505521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75029231.

The product of its (nonzero) digits is 80000, while the sum is 37.

Adding to 21224152505521 its reverse (12550525142212), we get a palindrome (33774677647733).

The spelling of 21224152505521 in words is "twenty-one trillion, two hundred twenty-four billion, one hundred fifty-two million, five hundred five thousand, five hundred twenty-one".