21113215115321 has 12 divisors (see below), whose sum is σ = 26004992447988. Its totient is φ = 17032509672192.

The previous prime is 21113215115309. The next prime is 21113215115327. The reversal of 21113215115321 is 12351151231112.

It can be written as a sum of positive squares in 2 ways, for example, as 12383790321721 + 8729424793600 = 3519061^2 + 2954560^2 .

It is not a de Polignac number, because 21113215115321 - 2¹⁸ = 21113214853177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21113215115327) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12672997436 + ... + 12672999101.

It is an arithmetic number, because the mean of its divisors is an integer number (2167082703999).

Almost surely, 2^{21113215115321} is an apocalyptic number.

It is an amenable number.

21113215115321 is a deficient number, since it is larger than the sum of its proper divisors (4891777332667).

21113215115321 is a wasteful number, since it uses less digits than its factorization.

21113215115321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25345996568 (or 25345996561 counting only the distinct ones).

The product of its digits is 1800, while the sum is 29.

Adding to 21113215115321 its reverse (12351151231112), we get a palindrome (33464366346433).

The spelling of 21113215115321 in words is "twenty-one trillion, one hundred thirteen billion, two hundred fifteen million, one hundred fifteen thousand, three hundred twenty-one".