21012022021021 has 16 divisors (see below), whose sum is σ = 21973748811264. Its totient is φ = 20054330463024.

The previous prime is 21012022021013. The next prime is 21012022021037. The reversal of 21012022021021 is 12012022021012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21012022021021 - 2³ = 21012022021013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012022020986 and 21012022021004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012022021051) 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, 42420630 + ... + 42913096.

It is an arithmetic number, because the mean of its divisors is an integer number (1373359300704).

Almost surely, 2^{21012022021021} is an apocalyptic number.

It is an amenable number.

21012022021021 is a deficient number, since it is larger than the sum of its proper divisors (961726790243).

21012022021021 is a wasteful number, since it uses less digits than its factorization.

21012022021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496560.

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

Adding to 21012022021021 its reverse (12012022021012), we get a palindrome (33024044042033).

Subtracting from 21012022021021 its reverse (12012022021012), we obtain a palindrome (9000000000009).

The spelling of 21012022021021 in words is "twenty-one trillion, twelve billion, twenty-two million, twenty-one thousand, twenty-one".