21113200100021 has 4 divisors (see below), whose sum is σ = 21310519727232. Its totient is φ = 20915880472812.

The previous prime is 21113200099963. The next prime is 21113200100059. The reversal of 21113200100021 is 12000100231112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21113200100021 - 2³⁸ = 20838322193077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21113200099969 and 21113200100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113200100521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98659813445 + ... + 98659813658.

It is an arithmetic number, because the mean of its divisors is an integer number (5327629931808).

Almost surely, 2^{21113200100021} is an apocalyptic number.

It is an amenable number.

21113200100021 is a deficient number, since it is larger than the sum of its proper divisors (197319627211).

21113200100021 is a wasteful number, since it uses less digits than its factorization.

21113200100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197319627210.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21113200100021 its reverse (12000100231112), we get a palindrome (33113300331133).

The spelling of 21113200100021 in words is "twenty-one trillion, one hundred thirteen billion, two hundred million, one hundred thousand, twenty-one".