21222121101021 has 96 divisors (see below), whose sum is σ = 34126920051840. Its totient is φ = 13024372320000.

The previous prime is 21222121101011. The next prime is 21222121101079. The reversal of 21222121101021 is 12010112122212.

21222121101021 is a `hidden beast` number, since 212 + 221 + 211 + 0 + 1 + 0 + 21 = 666.

It is not a de Polignac number, because 21222121101021 - 2⁷ = 21222121100893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21222121100985 and 21222121101003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222121101011) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 100200591 + ... + 100412163.

It is an arithmetic number, because the mean of its divisors is an integer number (355488750540).

Almost surely, 2^{21222121101021} is an apocalyptic number.

It is an amenable number.

21222121101021 is a deficient number, since it is larger than the sum of its proper divisors (12904798950819).

21222121101021 is a wasteful number, since it uses less digits than its factorization.

21222121101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211912 (or 211887 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21222121101021 its reverse (12010112122212), we get a palindrome (33232233223233).

The spelling of 21222121101021 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty-one million, one hundred one thousand, twenty-one".