21001200200221 has 16 divisors (see below), whose sum is σ = 21809470676400. Its totient is φ = 20198558822400.

The previous prime is 21001200200191. The next prime is 21001200200231. The reversal of 21001200200221 is 12200200210012.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2625660511321 + 18375539688900 = 1620389^2 + 4286670^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001200200221 - 2²⁹ = 21000663329309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001200200231) 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 15 ways as a sum of consecutive naturals, for example, 51760381 + ... + 52164541.

It is an arithmetic number, because the mean of its divisors is an integer number (1363091917275).

Almost surely, 2^{21001200200221} is an apocalyptic number.

It is an amenable number.

21001200200221 is a deficient number, since it is larger than the sum of its proper divisors (808270476179).

21001200200221 is a wasteful number, since it uses less digits than its factorization.

21001200200221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411120.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21001200200221 its reverse (12200200210012), we get a palindrome (33201400410233).

The spelling of 21001200200221 in words is "twenty-one trillion, one billion, two hundred million, two hundred thousand, two hundred twenty-one".