21000002222221 has 16 divisors (see below), whose sum is σ = 22951235926080. Its totient is φ = 19055796584320.

The previous prime is 21000002222201. The next prime is 21000002222231. The reversal of 21000002222221 is 12222220000012.

It is a cyclic number.

It is not a de Polignac number, because 21000002222221 - 2⁵ = 21000002222189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000002222195 and 21000002222204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000002222201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106352841 + ... + 106550113.

It is an arithmetic number, because the mean of its divisors is an integer number (1434452245380).

Almost surely, 2^{21000002222221} is an apocalyptic number.

It is an amenable number.

21000002222221 is a deficient number, since it is larger than the sum of its proper divisors (1951233703859).

21000002222221 is a wasteful number, since it uses less digits than its factorization.

21000002222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215036.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21000002222221 its reverse (12222220000012), we get a palindrome (33222222222233).

The spelling of 21000002222221 in words is "twenty-one trillion, two million, two hundred twenty-two thousand, two hundred twenty-one".