21224524221021 has 16 divisors (see below), whose sum is σ = 32496879191040. Its totient is φ = 12186329695920.

The previous prime is 21224524220951. The next prime is 21224524221067. The reversal of 21224524221021 is 12012242542212.

It is not a de Polignac number, because 21224524221021 - 2²⁷ = 21224390003293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21224524221021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224524221221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16925457285 + ... + 16925458538.

It is an arithmetic number, because the mean of its divisors is an integer number (2031054949440).

Almost surely, 2^{21224524221021} is an apocalyptic number.

It is an amenable number.

21224524221021 is a deficient number, since it is larger than the sum of its proper divisors (11272354970019).

21224524221021 is a wasteful number, since it uses less digits than its factorization.

21224524221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33850915856.

The product of its (nonzero) digits is 10240, while the sum is 30.

Adding to 21224524221021 its reverse (12012242542212), we get a palindrome (33236766763233).

The spelling of 21224524221021 in words is "twenty-one trillion, two hundred twenty-four billion, five hundred twenty-four million, two hundred twenty-one thousand, twenty-one".