21113063523221 has 16 divisors (see below), whose sum is σ = 21521224340784. Its totient is φ = 20708820271104.

The previous prime is 21113063523197. The next prime is 21113063523229. The reversal of 21113063523221 is 12232536031112.

It can be written as a sum of positive squares in 8 ways, for example, as 2830170300721 + 18282893222500 = 1682311^2 + 4275850^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113063523221 - 2¹⁸ = 21113063261077 is a prime.

It is a super-2 number, since 2×21113063523221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113063523229) 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, 149141345 + ... + 149282841.

It is an arithmetic number, because the mean of its divisors is an integer number (1345076521299).

Almost surely, 2^{21113063523221} is an apocalyptic number.

It is an amenable number.

21113063523221 is a deficient number, since it is larger than the sum of its proper divisors (408160817563).

21113063523221 is a wasteful number, since it uses less digits than its factorization.

21113063523221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155320.

The product of its (nonzero) digits is 12960, while the sum is 32.

Adding to 21113063523221 its reverse (12232536031112), we get a palindrome (33345599554333).

The spelling of 21113063523221 in words is "twenty-one trillion, one hundred thirteen billion, sixty-three million, five hundred twenty-three thousand, two hundred twenty-one".