21102133321021 has 4 divisors (see below), whose sum is σ = 21102181662492. Its totient is φ = 21102084979552.

The previous prime is 21102133321019. The next prime is 21102133321063. The reversal of 21102133321021 is 12012333120112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16396101624100 + 4706031696921 = 4049210^2 + 2169339^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102133321021 - 2¹ = 21102133321019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102133320983 and 21102133321001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102133321121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23509930 + ... + 24391003.

It is an arithmetic number, because the mean of its divisors is an integer number (5275545415623).

Almost surely, 2^{21102133321021} is an apocalyptic number.

It is an amenable number.

21102133321021 is a deficient number, since it is larger than the sum of its proper divisors (48341471).

21102133321021 is an equidigital number, since it uses as much as digits as its factorization.

21102133321021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48341470.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21102133321021 its reverse (12012333120112), we get a palindrome (33114466441133).

The spelling of 21102133321021 in words is "twenty-one trillion, one hundred two billion, one hundred thirty-three million, three hundred twenty-one thousand, twenty-one".