21011020200221 has 4 divisors (see below), whose sum is σ = 21017979799200. Its totient is φ = 21004060601244.

The previous prime is 21011020200199. The next prime is 21011020200271. The reversal of 21011020200221 is 12200202011012.

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 a de Polignac number, because none of the positive numbers 2^k-21011020200221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011020200196 and 21011020200205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011020200271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3479794961 + ... + 3479800998.

It is an arithmetic number, because the mean of its divisors is an integer number (5254494949800).

Almost surely, 2^{21011020200221} is an apocalyptic number.

It is an amenable number.

21011020200221 is a deficient number, since it is larger than the sum of its proper divisors (6959598979).

21011020200221 is an equidigital number, since it uses as much as digits as its factorization.

21011020200221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6959598978.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21011020200221 its reverse (12200202011012), we get a palindrome (33211222211233).

The spelling of 21011020200221 in words is "twenty-one trillion, eleven billion, twenty million, two hundred thousand, two hundred twenty-one".