21021012002221 has 16 divisors (see below), whose sum is σ = 26208140404608. Its totient is φ = 16379930952000.

The previous prime is 21021012002213. The next prime is 21021012002233. The reversal of 21021012002221 is 12220021012012.

It is a happy number.

It is not a de Polignac number, because 21021012002221 - 2³ = 21021012002213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021012002195 and 21021012002204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021012002021) 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, 19581991 + ... + 20627563.

It is an arithmetic number, because the mean of its divisors is an integer number (1638008775288).

Almost surely, 2^{21021012002221} is an apocalyptic number.

It is an amenable number.

21021012002221 is a deficient number, since it is larger than the sum of its proper divisors (5187128402387).

21021012002221 is a wasteful number, since it uses less digits than its factorization.

21021012002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1306692.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21021012002221 its reverse (12220021012012), we get a palindrome (33241033014233).

The spelling of 21021012002221 in words is "twenty-one trillion, twenty-one billion, twelve million, two thousand, two hundred twenty-one".