21113011523221 has 16 divisors (see below), whose sum is σ = 21400401787200. Its totient is φ = 20827471137408.

The previous prime is 21113011523213. The next prime is 21113011523231. The reversal of 21113011523221 is 12232511031112.

It is a cyclic number.

It is not a de Polignac number, because 21113011523221 - 2³ = 21113011523213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113011523231) 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, 24210115 + ... + 25067023.

It is an arithmetic number, because the mean of its divisors is an integer number (1337525111700).

Almost surely, 2^{21113011523221} is an apocalyptic number.

It is an amenable number.

21113011523221 is a deficient number, since it is larger than the sum of its proper divisors (287390263979).

21113011523221 is a wasteful number, since it uses less digits than its factorization.

21113011523221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 857988.

The product of its (nonzero) digits is 720, while the sum is 25.

Adding to 21113011523221 its reverse (12232511031112), we get a palindrome (33345522554333).

The spelling of 21113011523221 in words is "twenty-one trillion, one hundred thirteen billion, eleven million, five hundred twenty-three thousand, two hundred twenty-one".