21022120022021 has 16 divisors (see below), whose sum is σ = 22566600096048. Its totient is φ = 19511920742400.

The previous prime is 21022120022009. The next prime is 21022120022143. The reversal of 21022120022021 is 12022002122012.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1416361812100 + 19605758209921 = 1190110^2 + 4427839^2 .

It is a cyclic number.

It is not a de Polignac number, because 21022120022021 - 2³⁴ = 21004940152837 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022120024021) 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, 8346281 + ... + 10569041.

It is an arithmetic number, because the mean of its divisors is an integer number (1410412506003).

Almost surely, 2^{21022120022021} is an apocalyptic number.

It is an amenable number.

21022120022021 is a deficient number, since it is larger than the sum of its proper divisors (1544480074027).

21022120022021 is a wasteful number, since it uses less digits than its factorization.

21022120022021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2230472.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21022120022021 its reverse (12022002122012), we get a palindrome (33044122144033).

The spelling of 21022120022021 in words is "twenty-one trillion, twenty-two billion, one hundred twenty million, twenty-two thousand, twenty-one".