21021022120221 has 16 divisors (see below), whose sum is σ = 31143040843200. Its totient is φ = 14013661114224.

The previous prime is 21021022120211. The next prime is 21021022120229. The reversal of 21021022120221 is 12202122012012.

It is a happy number.

21021022120221 is a `hidden beast` number, since 2 + 10 + 210 + 221 + 2 + 0 + 221 = 666.

It is not a de Polignac number, because 21021022120221 - 2³⁷ = 20883583166749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21021022120194 and 21021022120203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021022120229) 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, 8731131 + ... + 10875416.

It is an arithmetic number, because the mean of its divisors is an integer number (1946440052700).

Almost surely, 2^{21021022120221} is an apocalyptic number.

It is an amenable number.

21021022120221 is a deficient number, since it is larger than the sum of its proper divisors (10122018722979).

21021022120221 is a wasteful number, since it uses less digits than its factorization.

21021022120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19646265 (or 19646259 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21021022120221 its reverse (12202122012012), we get a palindrome (33223144132233).

The spelling of 21021022120221 in words is "twenty-one trillion, twenty-one billion, twenty-two million, one hundred twenty thousand, two hundred twenty-one".