21000212002221 has 8 divisors (see below), whose sum is σ = 28000308719424. Its totient is φ = 14000128309920.

The previous prime is 21000212002207. The next prime is 21000212002229. The reversal of 21000212002221 is 12220021200012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21000212002221 - 2¹³ = 21000211994029 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000212002221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000212002229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1497081 + ... + 6651441.

It is an arithmetic number, because the mean of its divisors is an integer number (3500038589928).

Almost surely, 2^{21000212002221} is an apocalyptic number.

It is an amenable number.

21000212002221 is a deficient number, since it is larger than the sum of its proper divisors (7000096717203).

21000212002221 is a wasteful number, since it uses less digits than its factorization.

21000212002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6512451.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21000212002221 its reverse (12220021200012), we get a palindrome (33220233202233).

The spelling of 21000212002221 in words is "twenty-one trillion, two hundred twelve million, two thousand, two hundred twenty-one".