21240200135213 has 4 divisors (see below), whose sum is σ = 21240212047548. Its totient is φ = 21240188222880.

The previous prime is 21240200135159. The next prime is 21240200135233. The reversal of 21240200135213 is 31253100204212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 902237819044 + 20337962316169 = 949862^2 + 4509763^2 .

It is a cyclic number.

It is not a de Polignac number, because 21240200135213 - 2²⁰ = 21240199086637 is a prime.

It is a super-3 number, since 3×21240200135213³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240200135233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2681456 + ... + 7047737.

It is an arithmetic number, because the mean of its divisors is an integer number (5310053011887).

Almost surely, 2^{21240200135213} is an apocalyptic number.

It is an amenable number.

21240200135213 is a deficient number, since it is larger than the sum of its proper divisors (11912335).

21240200135213 is an equidigital number, since it uses as much as digits as its factorization.

21240200135213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11912334.

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 21240200135213 its reverse (31253100204212), we get a palindrome (52493300339425).

The spelling of 21240200135213 in words is "twenty-one trillion, two hundred forty billion, two hundred million, one hundred thirty-five thousand, two hundred thirteen".