21012211121021 has 8 divisors (see below), whose sum is σ = 21039081701088. Its totient is φ = 20985343650000.

The previous prime is 21012211121009. The next prime is 21012211121051. The reversal of 21012211121021 is 12012111221012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21012211121021 - 2¹⁴ = 21012211104637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012211121051) 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 7 ways as a sum of consecutive naturals, for example, 12901946 + ... + 14438996.

It is an arithmetic number, because the mean of its divisors is an integer number (2629885212636).

Almost surely, 2^{21012211121021} is an apocalyptic number.

It is an amenable number.

21012211121021 is a deficient number, since it is larger than the sum of its proper divisors (26870580067).

21012211121021 is a wasteful number, since it uses less digits than its factorization.

21012211121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1554523.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21012211121021 its reverse (12012111221012), we get a palindrome (33024322342033).

Subtracting from 21012211121021 its reverse (12012111221012), we obtain a palindrome (9000099900009).

The spelling of 21012211121021 in words is "twenty-one trillion, twelve billion, two hundred eleven million, one hundred twenty-one thousand, twenty-one".